What do you want to simulate today? Using GSSF - GSSF V2 - Operations M… · RD 9. GSSFP2.ICD.005...

What do you want to simulate today?

Using GSSF

By GSSF Team

Document Ref: GSSFP2.OM.001 Issue Date: 16 March 2005 Issue: 5 Revision 1 Filename: GSSFP2.OM.001 - Operations Manual - Issue 5

Revision 1.doc

Copyright © 2005 VEGA Group PLC All rights reserved.

No part of this work may be disclosed to any third party translated reproduced

copied or disseminated in any form or by any means except as defined in the contract or with the written permission of VEGA Group PLC.

VEGA Informations-Technologien GmbH Hilpertstraße 20A, D-64295 Darmstadt, Germany

Tel: +49 6151 8257-0 Fax: +49 6151 8257-99 www.vega-group.de

What do you want to simulate today? Using GSSF Contents • i

Contents

Chapter 1: Overview 1 About GSSF ...................................................................................................................................................1 Typographical Convention ...........................................................................................................................1 Scope of Document ........................................................................................................................................1 Hardware and Software Configuration.......................................................................................................1 Reporting Problems ......................................................................................................................................3

Background Information ...................................................................................................................3 Contact Us.........................................................................................................................................3

Reference Documents....................................................................................................................................3 System Internal ICDs ........................................................................................................................3 Model Internal ICDs .........................................................................................................................4 External ICDs....................................................................................................................................4

Applicable Documents ..................................................................................................................................4

Chapter 2: GSSF at a Glance 5 Global Navigation Satellite System Galileo.................................................................................................5 Galileo System Simulation Facility ..............................................................................................................5

Conceptual Summary and Objectives ...............................................................................................5 Simulation and Analysis Capabilities ...............................................................................................6 Modelling Capabilities ......................................................................................................................9 Interfacing Capabilities ...................................................................................................................11 Flexibility........................................................................................................................................11

Chapter 3: Getting Started 13 Starting GSSF..............................................................................................................................................13 Login and Start Page...................................................................................................................................14 The GSSF Workspace.................................................................................................................................14 File Structure in GSSF................................................................................................................................20 Managing Projects: The File Menu ...........................................................................................................21 Editing Projects: The Edit Menu ...............................................................................................................22 Executing Projects: Runtime Menu...........................................................................................................23 Search Window............................................................................................................................................26 Logging and Message Monitoring..............................................................................................................27 Getting Help.................................................................................................................................................28

Chapter 4: Simulating 29 Simulation Type...........................................................................................................................................29 Creating a New Simulation.........................................................................................................................29 Editing Simulation.......................................................................................................................................30

Specifying Data to Record ..............................................................................................................30 Visualisation of Recorded Data ......................................................................................................31

Set Simulation Time and TimeStep ...........................................................................................................33 Starting a Simulation ..................................................................................................................................35 Pausing and Resuming a Simulation .........................................................................................................36 Terminating a Simulation Early ................................................................................................................36 Scheduling Simulation – Batch Mode........................................................................................................36

ii • Contents What do you want to simulate today? Using GSSF

Changing Parameter Values at Run-Time................................................................................................40 Generating a Simulation Report ................................................................................................................42

Chapter 5: Configure Timeline 46 Specifying Feared Events................................................................................................................48 Specifying Failures .........................................................................................................................49 Specifiying Script Execution...........................................................................................................51

Chapter 6: Configure Scenario 53 Creating a New Scenario ............................................................................................................................53 Editing a Scenario .......................................................................................................................................54

Selecting Models and Algorithms...................................................................................................55 Defining a New Space Segment ..................................................................................................................56

Walker Wizard ................................................................................................................................57 Constellation File Wizard. ..............................................................................................................60 Empty Constellation........................................................................................................................61

Defining a New User Segment ....................................................................................................................64 Configure UERE for User Receiver................................................................................................67

Generating a Scenario Report....................................................................................................................75

Chapter 7: Analysing Data 77 Selecting/Editing Analyses..........................................................................................................................77 Defining Analysis Parameters ....................................................................................................................80

Selecting Elements - Analysis........................................................................................................80 Define Analysis Control Parameters ...............................................................................................81

Executing Analysis ......................................................................................................................................83 Defining Output-Data Visualisations.........................................................................................................83 Apply Mathematical function to Processed Data .....................................................................................84 Comparing Data ..........................................................................................................................................88 Extracting Grid Data ..................................................................................................................................90 RAMS Support in GSSF.............................................................................................................................92

Chapter 8: Visualising Data 93 Visualising Data on Time Plots ..................................................................................................................93 Visualising Data on Map Plots ...................................................................................................................98 Visualising Data on Radar Plots ..............................................................................................................104 Visualising Data on Pair Plots ..................................................................................................................107 Visualising Data on Stanford Plots ..........................................................................................................110 Saving Visualisations.................................................................................................................................113 Visualising Saved Data..............................................................................................................................114

Chapter 9: Modelling in GSSF 117 GSSF and Modelling .................................................................................................................................117 Modelling Capabilities in GSSF...............................................................................................................117

An Introduction to GSSF Code Generation ..................................................................................117 Model Definition...........................................................................................................................117 Attributes ......................................................................................................................................118

Model Development Guidelines................................................................................................................121 General Guidelines........................................................................................................................121 The Model Architecture ................................................................................................................121

Compiling and Integrating your Model...................................................................................................125 An Overview of the Model Development Life Cycle ...................................................................125 Example of the Model Development Cycle ..................................................................................127 Unit Testing ..................................................................................................................................129

Generating a Model Report......................................................................................................................131 Overview on Infrastructure API Functions ............................................................................................134

What do you want to simulate today? Using GSSF Contents • iii

More Information on GSSF Modelling ...................................................................................................135 Scheduler Models Interaction ..................................................................................................................135

Chapter 10: Importing and Exporting Data 137 GSSF - Importing and Exporting Data ...................................................................................................137 GSSF Supported Formats.........................................................................................................................137

Image Formats ..............................................................................................................................137 Constellation File Formats ............................................................................................................138 Data File Formats..........................................................................................................................138

Importing Data from an XML File..........................................................................................................138 Importing Data from a Constellation File...............................................................................................138 Reading IGS SP3 Files ..............................................................................................................................138 Reading RINEX Clock Files .....................................................................................................................139 Importing IONEX File..............................................................................................................................139 Importing TROPEX File ..........................................................................................................................141 Exporting Data to an ASCII File .............................................................................................................143 Exporting RINEX Observation and IGS SP3.........................................................................................144 Writing Images ..........................................................................................................................................144

Chapter 11: GSSF Tutorials 145 Tutorial 1: Analysing Global Availability of Integrity...........................................................................145

Preparation ....................................................................................................................................145 Loading Simulation.......................................................................................................................146 Selecting Analysis.........................................................................................................................147 Running Simulation ......................................................................................................................149 Visualising Result .........................................................................................................................150

Tutorial 2: Analysing Global Dilution of Precision ................................................................................154 Preparation ....................................................................................................................................154 Loading Simulation.......................................................................................................................154 Selecting Analysis.........................................................................................................................155 Running Simulation ......................................................................................................................157 Visualising Result .........................................................................................................................158

Tutorial 3: Generating RINEX Data .......................................................................................................161 Preparation ....................................................................................................................................161 Loading Simulation.......................................................................................................................161 Selecting Exporter.........................................................................................................................162 Running Simulation ......................................................................................................................164

Tutorial 4: Modify Algorithm using GSSF .............................................................................................167 Preparation ....................................................................................................................................167 Changing Model Specification......................................................................................................167 Generating Model Wrapper Source Code .....................................................................................168 Modifying Model Source Code.....................................................................................................168 Building Model Library ................................................................................................................169 Saving New Model Catalogue ......................................................................................................169

Chapter 12: System Administration 170 Installing GSSF..........................................................................................................................................170 Un-Installing GSSF ...................................................................................................................................172 Setting Up User Accounts and Privileges ................................................................................................174 Default User Accounts...............................................................................................................................179

Chapter 14: Troubleshooting 180 How to Handle Common Problems .........................................................................................................180

During Installation ........................................................................................................................180 At Runtime....................................................................................................................................180 Compatibility ................................................................................................................................180

Messaging...................................................................................................................................................180

iv • Contents What do you want to simulate today? Using GSSF

Software Problem Reporting....................................................................................................................181

APPENDIX A SVS REFERENCE SCENARIO 182

APPENDIX B RDG REFERENCE SCENARIO 183

APPENDIX C BINARY FILE FORMAT 184

Index 185

What do you want to simulate today? Using GSSF Chapter 1: Overview • 1

Chapter 1: Overview

This chapter includes information about the general features of GSSF.

About GSSF The Galileo System Simulation Facility (GSSF) is a software simulator tool that reproduces the functional and performance behavior of the Galileo system in order to support the Galileo definition, integration, verification, validation and operational phases. The development of the GSSF is divided into phases. The first phase has been completed with the delivery of the GSSF V1 Prototype. Lessons learned from this development lead to requirements applicable to the current GSSF V2 development. Further, post-V2, phases may be required to cover the whole Galileo lifecycle.

Typographical Convention Bold Type Text - The menu items and options are displayed in bold type.

Bold Italic Text - The node names are displayed in italic bold type.

Courier Type Text - Items that you must enter are displayed in courier type.

Scope of Document This Issue of the Operations Manual is intended for GSSF RC 2 that is targeted towards Service Volume and Raw Data Generation type Simulation. Note, simulation files generated with former (Beta) versions of GSSF can only be used with that individual version. From GSSF V2.0 onward, GSSF versions will be kept upward compatible.

The present volume of the operations manual is targeted towards how to use GSSF while RD 1 defines and provides references for the implemented models, algorithms and analyses. It is therefore recommended that the user identifies the task procedures in this document while referring to RD 1 for implementation details and default settings.

Hardware and Software Configuration The baseline hardware configuration is one Workstation (PC) as defined in Table 1. Future versions of GSSF are likely to use a distributed system that allows running computationally intensive algorithms on secondary workstations. The envisaged baseline for running heaviest algorithms is at

2 • Chapter 1: Overview What do you want to simulate today? Using GSSF

present based on three platforms, where OSPF and IPF share one each and the third one is for GSSF MMI and basic operations.

The minimum recommended hardware configuration for running the GSSF according to Table 2 is aimed at running GSSF with limited model fidelity but does not exclude the general GSSF capabilities. The high-end PC specification addressed above would provide optimal performance of GSSF.

The following software has to be installed on the same machine as GSSF:

• Operating System Windows 2000 or Windows XP (XP is recommended)

• .NET Framework 1.1, which is a necessary extension to your operating system.

To allow execution of certain visualisation features such as Map Plots, an installation of IDL 6.0 (runtime or development version) is required. Note, if IDL is not available GSSF will still run, however, only limited visualisation capability will be accessible.

Note, the simulation run-time environment SIMSAT 2000 does not have to be installed separately anymore as with previous GSSF versions. Any relevant functionality is now contained within the GSSF installation.

Table 1 - GSSF V2.0 Recommended Hardware Specification

Item Description

OS Windows XP (sp1)

Processors Dual Pentium Xeon 3.06 GHz

Ram 4 GB

HDD 584GB SCSI

Monitors Dual 19"

Network adapter Gigabit Ethernet

CD-ROM DVD-CDR-RW combo

Graphics adapter 128 Mb 3D accelerator, dual monitor capable

Misc UK Keyboard, button wheel optical mouse

Network switch 8 port Giga Ethernet switch

Table 2 - Minimum Hardware Specification

Item Description

OS Windows XP (sp1)

Processors Pentium 4 - 2GHz

Ram 512MB (1 GB recommended for future use in GSSF)

Drives HDD: 20GB (40GB recommended for future use in GSSF)

CDROM (for installation purposes)

Monitors 19”

Graphics adapter 64 MB 3D accelerator

What do you want to simulate today? Using GSSF Chapter 1: Overview • 3

Item Description

Network adaptor 100Mbit Ethernet

Misc UK Keyboard, button wheel mouse

Internet access preferably with IE6 (for downloads and access to GSSF portal).

Reporting Problems In case, if you encounter any problems with GSSF, please report them in a way that will help us to rectify the problems rapidly as instructed below. Fore more details please also refer to Section Software Problem Reporting.

When a software problem is encountered, it may be due to problems associated with the software or sometimes only occurs when running on a certain machine, operating systems or graphics devices. Apart from this it may be due to improper dependency software installation. In order to mitigate these problems please provide us with following information when raising a Software Problem Reporting (SPR).

• The version of GSSF you are running.

• The type of machine it is running on.

• The version of dependency software’s installed on the machine.

To report a problem, contact us at the following:

VEGA Informations-Technologien GmbH

GSSF Team

Hilpertstrasse 20A

64295 Darmstadt, Germany

Tel No: +49 (0) 6151 8257 0

Tel No: +49 (0) 6151 8257 99

mailto:[email protected]

http://www.vega.de/

Reference Documents The following is a list of documents with a direct bearing on the content of this report. Where referenced in the text, these are identified as RD.n, where 'n' is the number in the list below:

RD 1. GSSF Operations Manual, Volume 2, Algorithms and Models, GSSFP2.OM.002 Issue 4 Revision 1, March 2005

RD 2. Simulation Model Portability Handbook, SMP.REP.009-011, Issue 1 A0, ftp://ftp.estec.esa.nl/pub/was/smp/

RD 3. Software Design Document, GSSFP2.SDD.001, Volume 1, Issue 3, November 2003

RD 4. Software Design Document, GSSFP2.SDD.001 Volume 2, Issue 2, November 2003

RD 5. GSSFP2.ICD.001 - RunTime Environment - Issue 1 Revision 3

RD 6. GSSFP2.ICD.002 - Interface to Data Storage - Issue 2

RD 7. GSSFP2.ICD.004 - Scenario File Format - Issue 2

RD 8. GSSFP2.ICD.012 - Trajectory File Format - Issue 2

Background Information

Contact Us

System Internal ICDs

4 • Chapter 1: Overview What do you want to simulate today? Using GSSF

RD 9. GSSFP2.ICD.005 - User Rx Pos. Detn Alg Interface - Issue 2 - Revision 2

RD 10. GSSFP2.ICD.006 - User Rx Integ. Alg Interface - Issue 1 Rev 3

RD 11. GSSFP2.ICD.007 - OD&TS Algorithm Interface - Issue 2

RD 12. GSSFP2.ICD.008 - Ground Integrity Algorithm Interface - Issue 2

RD 13. GSSFP2.ICD.009 - Orbit Propagator Interface - Issue 2 Revision 1

RD 14. GSSFP2.ICD.010 - Tropospheric Alg Interface - Issue 2 Revision 1

RD 15. GSSFP2.ICD.011 - Ionospheric Alg Interface - Issue 2

RD 16. GSSFP2.ICD.015 - User Rx Algorithms - Issue 1 - Revision 2

RD 17. GSSFP2.ICD.017 - Multipath Model Interface - Issue 3 Revision 1

RD 18. GSSFP2.ICD.013 - RINEX, TROPEX and IONEX File Format - Issue 6

RD 19. GSSFP2.ICD.016 - EETES interface - Issue 1 Revision 2

RD 20. GSSFP2.ICD.018 - External Files - Issue 1 Revision 3

Applicable Documents The following is a list of applicable documents. Where referenced in the text, these are identified as AD.n, where 'n' is the number in the list below:

AD 1. System Requirements Document, GSSFP2.SRD.001, Volume 1 and 2, Issue 5, May 2003

Model Internal ICDs

External ICDs

What do you want to simulate today? Using GSSF Chapter 2: GSSF at a Glance • 5

Chapter 2: GSSF at a Glance

Global Navigation Satellite System Galileo Galileo will be an independent, global, European-controlled satellite-based navigation system. It consists of a Space Segment with a total of 30 satellites (27 + 3 in-orbit spares) in Medium-Earth Orbit (MEO) and a Ground Segment providing system and satellite monitoring and control, as well as an Integrity function to broadcast real-time warnings of satellite or system malfunctions. Galileo will provide navigation services of the following types:

• Open Service providing global positioning and timing services, free of charge;

• Safety-of-Life Service providing integrity services with a defined time-to-alarm limit;

• Commercial Service providing data dissemination services;

• Public Regulated Service providing global positioning and timing services.

Galileo will provide navigation services using satellites only and also using satellites augmented with local, ground-based systems providing supplementary navigation signals or data dissemination services, by means of local transmissions using either special-purpose equipment or existing navigation or communications systems.

Galileo System Simulation Facility GSSF is conceived as a simulations environment that reproduces the functional and performance behaviour of the Galileo system to support the entire Galileo programme lifecycle.

• System Design: GSSF supports analysis of system performance (producing Figures of Merit), generation of raw data in standard formats for use in other test beds and the validation of processing algorithms.

• System Implementation: GSSF is designed to form part of a system test bed or AIV platform, allowing real system elements to be integrated and validated before full-scale system integration.

• System Operation: GSSF is foreseen to support mission planning activities and logistic support activities. It can be used in procedure validation and control team training.

Although the immediate role of GSSF primarily lies in the Galileo design definition phase, it was developed with the longer-term phases of Galileo in mind, i.e. providing the hooks for possible enhancements for particular application, e.g. Hardware-in-the-Loop simulations.

Conceptual Summary and Objectives

6 • Chapter 2: GSSF at a Glance What do you want to simulate today? Using GSSF

GSSF provides a single simulator that uses alternative models depending upon the type of analysis the end-user wishes to perform.

• The Service Volume Simulation (SVS) capability of GSSF allows the analysis of the navigation and integrity performance over long time periods and over large geographical areas. In particular, GSSF SVS allows the user to assess all relevant Figures of Merit on global or regional grids or for individual positions. Such Figures of Merit are Visibility, Coverage, Geometry, DOP, Navigation Precision, Integrity and Service (including Critical Satellites) as well as the associated availability and continuity figures. In addition GSSF provides GPS/Galileo global Interference analysis as well as Link Budget and Error Budget analyses. A comprehensive list of available analyses is provided further below, while individual implementations are further detailed in RD 1

• The Raw Data Generation (RDG) capability of GSSF uses high fidelity models to generate GPS and Galileo observables acquired by Galileo Sensor Stations. This capability includes the definition of Feared Events and is suitable for the validation and tuning of OSPF and IPF algorithms.

Future versions of GSSF (V2.1) are targeted towards

• End-to-End System Performance Analyses (end-to-end navigation and integrity performance of the complete Galileo System) This is however not yet applicable for GSSF V2.0.

Much common functionality is applied across SVS and RDG. In particular the definition of scenarios and the execution of simulations match. The two prime applications of GSSF essentially only differ in the composition and fidelity of models applied. For detailed information on model implementation and default settings, please refer to RD 1.

GSSF enables simulation of the nominal system and also its various degraded modes, in a deterministic or probabilistic manner. The Space Segment and User Segment are not limited to Galileo and provide GPS and EGNOS related models.

GSSF V2.0 supports the following Analyses and associated Figures of Merit. They are further described in detail in RD 1.

Visibility Analyses

• Global or Regional Visibility: The global and regional visibility analysis outputs the maximum, minimum, and mean number of satellites in view for each node on a latitude and longitude grid over the simulation time period. The user can choose to filter the output returned based on the satellite constellation type.

• Global or Regional Visibility (long Run): For Visibility analysis involving high-resolution grid, that produces a large volume of recorded data. The analysis outputs the maximum, minimum, and mean number of satellites in view for each node on a latitude and longitude grid over the simulation time period. Please note that this long run analysis doesn’t provide instantenous data.

• Receiver to Satellite Visibility: The receiver to satellite visibility analysis returns the number of satellites in view at each time step, and the maximum, minimum, and mean number of satellites in view for each receiver over the simulation time period.

• Ground Segment to Satellite Extended Visibility: The Ground Segment to Satellite Extended Visibility Analysis returns the number of ground stations that have at least a certain number of

Simulation and Analysis Capabilities

Analyses that are Applicable to GSSF SVS


satellites in view, S, for every epoch of the simulation where S is greater than or equal to a threshold, N, that can be specified by the user. The default for the threshold, N, is [10].

Coverage Analyses

• Depth of Coverage: The Depth of Coverage analysis returns the number of ground stations in view at each time step, and the maximum, minimum, and mean number of ground stations in view for each satellite over the simulation time period.

• Global or Regional Depth of Coverage (DOC Map): The global and regional Depth of Coverage analysis supports the production of a global Depth of Coverage Map. Therefore, it outputs the number of ground stations in view for each satellite position on a latitude and longitude grid over the simulation time period.

• Ground Segment to Satellite Inverse Depth of Coverage: The Ground Segment to Satellite Inverse Depth of Coverage Analysis returns the number of satellites that have at least a certain number of ground stations in view, S, for every epoch of the simulation where S is greater than or equal to a maximum threshold, M, that can be specified by the user. The default for the maximum threshold, M, is [5].

• Ground Segment to Satellite Availability of Depth of Coverage: The Ground Segment to Satellite Availability of Depth of Coverage Analysis returns the percentage of time during a specified time interval that at least N number of satellites are visible to at least M number of ground stations. The parameters M and N can be configured by the user. Their default values are N=10 and M=5. The user can also choose to filter the output returned based on the ground station type.

• Independent Integrity Path Coverage: The Independent Integrity Path Coverage Analysis returns the number of independent integrity paths available during each time step on a global or regional basis.

Geometry Analyses

• Receiver to Satellite Geometry: The Receiver to Satellite Geometry Analysis returns a set of geometry data for every receiver and their visible satellites. The user can filter the results based upon receiver type.

DOP Analyses

• Global or Regional DOP: The Global or Regional DOP Analysis returns the mean, maximum, minimum, and 95 percentile DOP for each node on the longitude and latitude grid for a simulation.

• Global or Regional Availability of DOP: The Global or Regional Availability of DOP Analysis returns the percentage of time that a DOP value is below a user specified threshold for each node on the longitude and latitude grid for a simulation. This is computed for every DOP type that was computed during the simulation: TDOP, PDOP, GDOP, HDOP, and/or VDOP.

• User Receiver DOP: The User Receiver DOP Analysis returns the Minimum, maximum, average, and 95% DOP values for each user receiver.

• User Receiver Availability of DOP: The User Receiver Availability of DOP Analysis returns the percentage of time that a DOP value is below a user specified threshold for each user receiver over the


duration of a simulation. This is computed for every DOP type that was computed during the simulation: TDOP, PDOP, GDOP, HDOP, and/or VDOP.

Navigation Performance Analyses

• Global or Regional NSP: The Global and Regional Navigation System Precision Analysis, returns the mean, maximum, minimum, and 95 percentile NSP (overall, horizontal, vertical, and time) for each node on the longitude and latitude grid for a simulation.

• Global or Regional Availability of NSP without failures : The Global and Regional Availability of NSP Analysis without failures returns the percentage of time that an NSP value is below a user specified threshold at each node on the latitude and longitude grid over the duration of a simulation.

• Global or Regional Availability of NSP with failures : This analysis is a subset of the Service Availability Analysis. The Global or Regional Availability of NSP with failures Analysis returns the percentage of time that the conditions for instantaneous availability with respect to user specified NSP thresholds, were met during the simulation for each node of the coverage grid.

• Global or Regional Continuity of NSP a posteriori without failures : The Global and Regional Continuity of NSP a posteriori without Failures Analysis returns the continuity indicator at each node on the latitude and longitude grid over the duration of a simulation.

Integrity Analyses

• Global or Regional Integrity (Protection Levels) : The Global and Regional Integrity Analysis, returns the Horizontal and Vertical Protection Levels (mean, maximum, minimum, and 95 percentile) for each node on the longitude and latitude grid for a simulation.

• Global or Regional Availability of Integrity without failures : The Global or Regional Availability of Integrity Analysis returns the percentage of time that the protection level (RAIM/GIC/Combined) are below the alert limits (horizontal and vertical) for each node on the longitude and latitude grid throughout a simulation.

• Global or Regional Continuity of Integrity a posteriori without failures : The Global or Regional Continuity of Integrity a posteriori without Failures Analysis returns the continuity indicator (RAIM/GIC/Combined) for each node on the longitude and latitude grid throughout a simulation.

• Global or Regional Availability of Integrity with failures : This analysis is a subset of the Service Availability Analysis.The Global or Regional Availability of Integrity with failures Analysis returns the percentage of time that the conditions for instantaneous availability with respect to user specified Protection Level thresholds, were met during the simulation for each node of the coverage grid.

Service Analyses

• Global or Regional Availability of Service: The Global or Regional Availability of Service Analysis returns the percentage of time that the conditions for instantaneous availability were met during the simulation for each node of the coverage grid. The outputs are Availabilities (A0, A1, A2 and ACS) and average number of critical satellites for each node covering the simulation duration.


• Global or Regional Critical Satellites : This analysis is a subset of the Service Availability Analysis. It computes number of satellites above the user-specified protection level thresholds. Those satellites are recorded being critical. The outputs are Availabilities (A0, A1, A2 and ACS) and average number of critical satellites for each node covering the simulation duration.

Interference Analysis

• Global or Regional Interference: The Global or Regional Interference Analysis returns the mean, maximum, minimum, and 95 percentile values of the three interference-related parameters Total Power, Degradation, Power Ratio for each node on the longitude and latitude grid for a simulation.

Link Budget Analysis

• Link Budget (requires models that are currently associated to RDG): The Link Budget Analysis returns all parameters of the link budget Signal Power, Antenna Temperature, Free Space Loss, Receiver Antenna Gain, Transmitter Antenna Gain, Pointing loss for every transmitter-receiver pair at every epoch.

Error Budget Analysis

• Error Budget (requires models that are currently associated to RDG) : The Error Budget Analysis returns all parameters of the error budget Signal Power, Antenna Temperature, Free Space Loss, Receiver Antenna Gain, Transmitter Antenna Gain, Pointing loss for every transmitter-receiver pair at every epoch.

Hence, GSSF provides a single simulator that uses alternative models depending upon the type of analysis the end-user wishes to perform. The Space Segment and User Segment are not limited to Galileo and provide GPS and EGNOS related models. This is important from a user's perspective when evaluating performance improvements obtained through a combined use of different satellite navigation systems.

The GSSF models represent self-contained elements of the Galileo architecture divided into the following parts:

• Space Segment: provides models of the Galileo, GPS and EGNOS satellites.

• Environment: contains models of the main sources of perturbation on the satellite signal, which affect the performance of a navigation system.

• User Segment: In order to analyse navigation performance at user level, GSSF models the user receivers and the internal algorithms they use to produce navigation information.

• Ground Segment: provides models of the Galileo Ground Segment. In V2.0, the Ground Segment functionality is limited to what is required for SVS and RDG as defined in RD 1 (Ground Station positions and determination of Controlled Satellites).

In future, GSSF may also contain models of the Search and Rescue (SAR) system and local elements such as Pseudolites. Figure 1 provides an overview on the major GSSF model components as addressed above. Figure 2 provides an overview on the GSSF model definition for SVS type simulations. It illustrates participating models and algorithms for this application and the basic information flow between participating elements. Figure 3 illustrates the basic functional architecture for RDG. For further details, please refer to RD 1.

Analyses that are Applicable to GSSF RDG

Modelling Capabilities


Space Segment

User Receiver Demonstrators

Ground Segment

Local Component Demonstrators Local Components

Non-European Integrity Systems

User Receivers

EGNOS

Search & Rescue

Service Providers

MEO-LUT Beacon

COSPAS-SARSATMCC

Figure 1 - Representation of the Galileo components

Environment Visibility

User Receiver GridUser Receiver Grid

SatelliteKeplerian Orbit Propagator

Ideal Attitude

Service User Receiver GridService User Receiver Grid

Interference User Receiver GridInterference User Receiver Grid

Model

AlgorithmData flow

Segment

Model

AlgorithmData flow

SegmentSpace Segment

Environment

Coordinate Transformations

True RangeElevationAzimuthLine of SightDopplerUser Segment

Ground Segment

Ground Network

Satellite Positions

Visible SatellitesReceiver Positiuons

Ground Station PositionsControlled Satellites

Controlled Satellites

Figure 2 - GSSF for Service Volume Simulation


Environment Models

Satellite Models

Environment

Ground Segment

Galileo Sensor Station

Space Segment

Satellite Signals

Visible Satellite Affected SignalsStation Position

RINEX/SP3 Data

Figure 3 - GSSF for Raw Data Generation

GSSF provides several internal and external interfaces that are of interest for the user to exchange the related algorithms or ingest external data. (RINEX, TROPEX, IONEX, IGS SP3, IGS ERP, TLES, YUMA, JGM3, JPL DE405). Examples of where this is used include initialisation of constellations (including actual GPS position data) as well as replacing environmental models with corresponding external data (Ionosphere/ Troposphere). These interfaces are covered in the related Interface Control Documents (see list of reference documents in Section Reference Documents).

The Export feature allows the User to ingest data produce by GSSF into other tools for further analysis (RINEX/SP3). GSSF also supports the feature of exporting simulation output data and analysis to ASCII files, i.e “Comma Separated Values” (CSV) files, which can be read by Microsoft Excel. For maximum flexibility, GSSF provides a built-in Exporter Catalogue, where custom made exporters can be incorporated into GSSF.

Image Formats: GSSF is fully compatible in writing the following graphic file formats. The types of graphic file that are supported by GSSF are JPG, JPEG, BMP, DIB.

Constellation File Formats: GSSF can read the following file formats to set the constellation parameters for the space segment and this is useful to significantly accelerate the prolonged process of entering the constellation details manually. The types of constellation files supported are IGS SP3, YUMA, RINEX.

Importing Data from an XML File: GSSF exclusively uses XML Datasets for saving Simulation results. This XML Dataset can be used to analyse and visualise any pre-recorded results.

For further details and related procedures, please refer to Section Chapter 10: Importing and Exporting Data.

Due to the evolving nature of the Galileo system and a diverse set of expected users, GSSF has to provide more flexibility and openness than traditional space system simulators. The users want to be able to add and remove Galileo elements within the simulation, select models with different levels of fidelity, select different algorithms, and change a simulation from a system simulation to a service volume simulation, all without recompiling the models. These requirements have lead to the need for a GSSF

Interfacing Capabilities

Flexibility


infrastructure and model architecture that will support this level of flexibility.

The design of the infrastructure and model architecture is component and interface based. A model catalogue is provided, where users can select from component models that can be added into a simulation.

The validation support of algorithms used in the Galileo system is an important role of GSSF. The component model approach provides a “plug-in” capability to introduce new algorithms in different areas.

The component-based modelling approach is complemented by the use of the Extensible Markup Language (XML) providing model meta-data (e.g. interface descriptions, documentation). This data is used by the GSSF infrastructure to present model information to the user e.g. supporting their understanding of the models.

For further details on GSSF model development support, please refer to Section Chapter 9: Modelling in GSSF.

What do you want to simulate today? Using GSSF Chapter 3: Getting Started • 13

Chapter 3: Getting Started

Starting GSSF The user launches GSSF by double clicking on "GSSF V2.0" Icon on the desktop of the PC. GSSF can also be started from windows, Start Menu by navigating through "Programs Galileo System Simulation Facility GSSF V2.0"

[Note: GSSF is available to all users ,only if the option is selected during installation of GSSF]

Figure 1: GSSF Desktop Icon

The application will start and display a “Splash Screen” with the GSSF logo. Status information is displayed on the bottom of this splash screen during initialisation.

Figure 2: Splash Screen

14 • Chapter 3: Getting Started What do you want to simulate today? Using GSSF

Login and Start Page After the user has launched GSSF, a login dialogue is displayed and GSSF users have to enter the user name and password to login.

Figure 3: Login Dialogue

After typing in user name and password, GSSF checks whether the account that the user has used to log in to the system has privileges to access GSSF at all. If so, then the GSSF Workspace interface is displayed. If the user has no privileges to access GSSF, the user is given the possibility to type in another account name and password.

For more information on System Administration including Default User Accounts, Creating New Accounts and Profiles, please refer to Section Chapter 12: System Administration.

The GSSF Workspace After Logging in, the GSSF displays the workspace customized for the profile that has been assigned to the user. The workspace made up of left, center, right and bottom pane with Simulation Explorer, Center Workspace Console, Property Grid of selected element and Runtime Console respectively.

Figure 4: GSSF – Workspace


It is highly recommended that GSSF users should become familiar with the working environment before carrying out any tasks. The user interface for all tasks performed with the Galileo System Simulation Facility is similar to Window's.

GSSF users, can find features like drop-down list, explorer view, pull-down menu, context menu, tab-widget window and this provides an user friendly graphic user interface.

A view of "File Menu" is shown below. The option available and their respective functions are described in section Managing Projects: The File Menu.

Figure 5: File Menu

In the center of the workspace a tab widget menu is available that the user can switch between via tab controls. This control provides Workspace Messages, Output, Runtime Controller and Runtime Messages, windows arranged in tabs. Clicking on them can access all the tabs.

Figure 6: Center Workspace Tab Widget-Windows

On the left side of the workspace, the user can find a set of explorer views stacked in tab widget windows namely Simulation Explorer, Model Catalogue Explorer, Analysis Catalogue Explorer, Visualisation Catalogue Explorer, Data Storage Explorer, Exporter Catalogue Explorer, and User Community Explorer. The windows displayed depend on the profile of the login user. A sample view of Model Catalogue is shown below.


Figure 7: Model Catalogue Explorer

In the above picture, if the user wants to pin this window so that it disappear's, the highlighted button must be clicked. This will change the appearance as illustrated below and the explorer will become visible only on placing the mouse cursor over the vertical menu on the left.

Figure 8: Model Catalogue Explorer [Pinned]

Similarly, in original state the simulation explorer view displays the tab of widget window's as marked in the following image and GSSF users can access them by clicking on the respective tab.


Figure 9: Simulation Explorer

The property grid, on the right hand side, contains the properties of element you have selected in the workspace. Properties of the selection can be viewed and edited from the property grid. The property grid can also be pinned by clicking on the pin icon and restored again by clicking on the same pin icon.. This feature is also available for Runtime Controller window.


Figure 10: Property Grid View

Simulation Summary is an important feature of GSSF centre workspace. When GSSF is started, the central part contains the "Simulation Summary" page shown below. This provides summary information on the simulation currently selected and the contents depends on the simulation type. The GSSF users can generate "Summary Report" by clicking on the "Generate Report" button. The summary element is divided into sections and detailed contents of the each section can be obtained in text file by clicking on the "[Details…]" link. Similarly a element can be hidden or expanded by clicking on the "<<" control button.


Figure 11: Simulation Summary


File Structure in GSSF GSSF, by default is designed to be flexible and offers the advantage to the users to select the location for storing the Simulation (*.gssf ) , Scenario (*.xsco) and associated files such as Timeline (*.time) , UERE (*.uere) .

The file structure is made up of 5 levels. GSSF users, have the option to select the location of the files in 1st tier, where as other files are stored within the 1 level location. The schematic representation of the file structure is given below.

Figure 12: GSSF - File Structure Schematic

Note: AND, GRD, and Job files are stored manually by the GSSF operator at user specified location for these files. This is also applicable for UERE and Timeline files, in case the GSSF Operator selects a different location manually.


Managing Projects: The File Menu The File menu offers the following entries, which allow for management of simulations in GSSF. Note that the entries of the menu and submenus depend on the context and the user profile’s settings:

Figure 13: GSSF - File Menu

• New: Using this option the user is able to generate new instances of Simulation (see section Creating a New Simulation), Scenario (see section Creating a New Scenario), Model Catalogue (see section Chapter 9: Modelling in GSSF), Analysis Catalogue (see section Chapter 7: Analysing Data), Visualisation Catalogue (see section Chapter 8: Visualising Data), Data Storage (see section Chapter 10: Importing and Exporting Data), DataSet (see section Chapter 10: Importing and Exporting Data), Exporter Catalogue or User Community. The available subentries depend on the user profile with the associated permissions.

• Open: Via this option the user is able to open existing files of Simulation (see section Creating a New Simulation), Scenario (see section Creating a New Scenario), Model Catalogue (see section Chapter 9: Modelling in GSSF), Analysis Catalogue (see section Chapter 7: Analysing Data), Visualisation Catalogue (see sectionChapter 8: Visualising Data ), Data Storage (see section Chapter 10: Importing and Exporting Data), DataSet (see sectionChapter 10: Importing and Exporting Data), Exporter Catalogue or User Community. The available subentries depend on the user profile with the associated permissions.

• Save: Depending on the currently selected node and whether this node has been modified, this option saves either a Simulation, a Scenario, a Model Catalogue, an Analysis Catalogue, a Visualisation Catalogue, a Data Storage, a DataSet, an Exporter Catalogue or an User Community to its associated file. The associated file name is appended to the Save menu option.

• Save As: This is like Save except for the difference that a Save As dialogue pops up and the user can define a different file name and a different directory where to store the output. This option is always available.


• Save All: This prompts GSSF to save all modifications to file, i.e Simulation, Scenario, Model Catalogue, Analysis Catalogue, Visualisation Catalogue, Data Storage, Exporter Catalogue or User Community, whatever has been modified.

• Import: This menu allows importing data into GSSF and depends on the current context. For example it might offer to import a satellite constellation file, which defines a new satellite constellation in the space segment.

• Export: This menu allows exporting data or graphics from GSSF and depends on the current context. For example it might offer to export a GRD to a file.

• Close: Depending on the currently selected, this option closes either a Simulation, a Scenario, a Model Catalogue, an Analysis Catalogue, a Visualisation Catalogue, a Data Storage, a DataSet, an Exporter Catalogue or an User Community.

• Close All: This option closes all files, i.e. Simulation, Scenario, Model Catalogue, Analysis Catalogue, Visualisation Catalogue, Data Storage, DataSet, Exporter Catalogue and User Community.

• Exit: This selection will exit the GSSF application. The user is asked to confirm that he wants to exit.

Editing Projects: The Edit Menu The Edit menu offers the following entries, which allow for editing the currently selected node. Note that the entries of this menu depend on the context and the user profile’s settings:

Figure 14: GSSF - Edit Menu

• Cut: The currently selected node is cut from the corresponding explorer (simulation explorer view, model catalogue explorer view, analysis catalogue explorer view, visualisation explorer view, data storage explorer view, exporter catalogue explorer view or user community explorer view) into the clipboard.

• Copy: The currently selected node is copied from the corresponding explorer (simulation explorer view, model catalogue explorer view, analysis catalogue explorer view, visualisation explorer view, data storage explorer view, exporter catalogue explorer view or user community explorer view) into the clipboard.

• Paste: The contents of the clipboard are pasted as a subentry to the currently selected node. This option is only available, if the contents of the clipboard logically belong to the currently selected node.

• Delete: The currently selected node is deleted from the corresponding explorer view (simulation explorer view, model


catalogue explorer view, analysis catalogue explorer view, visualisation explorer view, data storage explorer view, exporter catalogue explorer view or user community explorer view). Note that the user is not asked to confirm whether the selected node shall be deleted.

• Search: This option brings up the search window in the lower middle of the GSSF workspace (see section Search Window).

Executing Projects: Runtime Menu The Runtime menu allow for execution and control of simulations. Note that the entries of this menu depend on the context and the user profile’s settings:

Figure 15: GSSF – Run-Time Menu

Batch: This menu offers control of the batch mode Simualtion run's in GSSF:

Figure 16: GSSF – Batch Menu

• Open: This option allows you to read a file into GSSF with scheduled simulation jobs. When selected a file open dialogue is presented.

• Save: This option allows you to save the currently scheduled simulation runs into a simulation jobs file. When selected a file save dialogue is presented.

• Start: This starts the batch mode and GSSF takes control of the execution of the currently scheduled simulation jobs. If no simulation jobs are scheduled, this option is disabled.

• Pause: This option pauses the batch mode of GSSF. It is only available if batch mode has been started.

• Continue: This option continues with the previously paused batch mode and the corresponding simulation runs.


• Reset: This option resets all scheduled simulation jobs.

• Abort: This option aborts the currently active batch mode. It is only available if batch mode has been started.

Job: This menu offers control of GSSF runtime environment:

Figure 17: GSSF – Job Menu

• Start: This option starts the currently selected simulation in the Runtime Controller in the lower middle of the GSSF workspace. It is only available if a simulation has been paused or queued. Note: a new simulation is started by means of the Tools->Run option.

• Pause: This option pauses a currently selected and running simulation. It is only available when the selected simulation is queued.

• Continue: This option continues execution of a previously paused simulation.

• Abort: This option terminates the currently running or paused simulation early.

• Remove: This option removes a simulation entry from the Runtime Controller. It is only available if a simulation is finished or aborted.

Alphanumeric Display: GSSF users can view data and edit parameters during Run-Time, which are not part of default simulation parameters using Alpha-Numeric Displays (AND):

Figure 18: Alphanumeric Display Menu

• New: This option creates a new and empty Alpha-Numeric Display in the central application area of GSSF.

• Open: This option allows opening a previously defined and saved Alpha-Numeric Display. When selected a file open dialogue is displayed.


• Save: This option allows saving the configuration of the currently selected Alpha-Numeric Display. When selected a file save dialogue is displayed.

• Delete Item: This option deletes the currently selected item from the Alpha-Numeric Display.

Graphical Display: GSSF users can visualise real time graphical plots using Graphic Display (GRD) components:

Figure 19: Graphical Display Menu

• New: This option creates a new and empty Graphical Display in the central application area of GSSF.

• Open: This option allows opening a previously defined and saved Graphical Display. When selected a file open dialogue is displayed.

• Save: This option allows saving the configuration of the currently selected Graphical Display. When selected a file save dialogue is displayed.

• Save Image: This option allows saving the currently selected Graphical Display as image. When selected a file save dialogue is displayed supporting the graphics file formats JPEG, GIF and Bitmap.

• Print: This option offers to print the currently selected Graphical Display. When selected a print dialogue is presented.

• Print Preview: This option offers to watch a print preview of the currently selected Graphical Display.

Logger: GSSF users have access to runtime message by means of the logger:


Figure 20: Logger Menu

• Show: This option brings up the Runtime Messages window in the lower middle of GSSF. For each message the window shows a column with an index, a column with the simulation time associated with the message, a column for source of the message, a column for type of the message and a column for the message itself.

• Open: This option offers to load a previously saved log file back into the Runtime Messages window. When selected a file open dialogue is presented.

• Save: This option allows saving the contents of the Runtime Messages window to a log file. When selected a file save dialogue is displayed.

• Print: This option allows printing the contents of the Runtime Messages window. When selected a print dialogue is shown.

• Print Preview: This option offers a print preview of the current contents of the Runtime Messages window.

Search Window GSSF users can search for elements by using in built search feature. In the Edit menu select "Search" option to display the widget window. Click on the tab “Search” marked below, to search for elements in the simulation on the tab menu in centre of workspace.

Figure 21: Search Window

A feature to search for Simulation, Model Catalogue, and Analysis Catalogue with options using name or by file type is available through the “Options” button in the Search Window.


Figure 22: Find Options

This feature provides user to use abbreviated search by typing initial word of element to be searched. In addition, user can specify the element to be searched by selecting the respective check box. It is also possible to select multiple elements that were searched in the list and editing their common values in the property grid. As stated earlier, if the "Search" window is closed or not available the user can open it from the Edit menu.

Logging and Message Monitoring "Output" panel, provides log of events that are encountered while connecting, running and disconnecting to a simulation kernel and while analysing recorded results. It provides the date, timestamp, and duration taken for Simulation, Analysis sequence.

Figure 23: Output Window

“Runtime Messages” panel can be found next to "Output" panel. This control provides status information of the processes carried out by the system. It contains information about the simulation components and the corresponding messages indicating the status of components deployed along with sim-time and source.

Figure 24: Event Logger


“Workspace Messages” panel provides status information of the processes carried out by the system. It contains information about the currently active window in the Workspace.

Figure 25: Workspace Messages

Getting Help The GSSF workspace has an interactive keyword based help, which provides the operator with online guide. Pressing "F1" key will display this help. For help on any specific component available in GSSF select the component and on pressing the "F1" key, the help topics that match with the component selected is displayed.

Also, in the menu bar select the 'Help' menu and navigate to 'Content', 'Index', and 'Search' sections to open the relevant sections of the help file.

Figure 26: Help File Menu

What do you want to simulate today? Using GSSF Chapter 4: Simulating • 29

Chapter 4: Simulating

Simulation Type GSSF V2.0 provides two dedicated types of simulation that the user may select:

• Service Volume Simulation, applying low fidelity models, in particular a user receiver grid subject to an environment characterised by a UERE budget. SVS in particular supports global and regional analyses to evaluating Figures of Merit according to Section 2.2.2.

• Raw Data Generation, applying high fidelity models including a high fidelity environment and producing data in standard formats (GPS & Galileo data in RINEX and SP3) for use in Galileo-related test beds.

Creating a New Simulation These steps will provide walkthrough in creating a new Simulation.

• Start GSSF and login as "Engineer".

• In order to add a new simulation, click on the File menu and navigate on to File New Simulation.

Figure 1: File Menu

• A "Select a Simulation type" dialogue window providing a list of simulation types is displayed; the user can select the type of simulation needed and click the "OK" button to add the simulation.

30 • Chapter 4: Simulating What do you want to simulate today? Using GSSF

Figure 2: Select Simulation Type

Editing Simulation Simulation is a container that has Scenario, Analyses, Recorder, Visualisation and Script Engine as main elements. All these elements contain sub-elements and changing values, removing or adding any of these elements or sub elements constitute editing of simulation. Hence it is recommended referring to each section individually in order to gain a better knowledge of the individual element.

The Recorder is used record data for element during a Simulation. By default Simulations have a Recorder attached. The User has to specify the data to be recorded by adding a variable to the Recorder .In case if the user wants to categorise the recording variables "RecorderCategory" can be used to hold multiple recording variables. Select and click right mouse button on "Recorder" and navigate through Add Variable.

Figure 3: Recorder Menu

This action will display a "Select Property for Recorder" list box with explorer view of all the elements that are available within the Simulation,

Specifying Data to Record


that the Recorder is associated with, and the user has to select the Variable to be recorded in the right pane and Click the OK button.

Figure 4: Recorder Property Selection

In the property grid frequency to specify the recording time steps can also be configured. The added variable values will be recorded at the specified time steps. The recorded file name 'RecorderOutput.xml' in XML format can be found in the execution folder with relevant date and time stamp.

Figure 5: Recorder Property Grid

The recorded file name 'RecorderOutput.xml' in XML format can be found in the execution folder with relevant date and time stamp.

In order to visualise recorded data the User has to add a visualisation to the ‘Visualisations’ node of the simulation. Select and click right mouse button on "Visualisations" and navigate through Add Visualisation.

Visualisation of Recorded Data


Figure 6: Add Visualisation for Recorded Data

This action will add a time series visualisation to the simulation, which automatically has assigned the recorded data to be visualised.

Figure 7: Time Series Visualisation of Recorded Data

In order to show the visualization of the recorded data the user needs to select ‘Show’ from the Visualisation node.


Figure 8: Show Recorded Data Visualisation

Set Simulation Time and TimeStep In order to set the simulation start, stop time and time step, the GSSF operator must select the simulation node in the simulation explorer on the left widget pane.

Figure 9: Select Simulation Node

In the property grid on the right side of GSSF workspace, select and expand the StartTime property in Simulation category.


Figure 10: Simulation Property Grid

Now select the Date row and click on the drop-down combo list to select the date,month and year for starting the simulation and select the Time row and edit the start time for the given or selected date.

NOTE: All the parameters can be keyed in manually without using the combo list or drop-down view on the relevant fields.

Figure 11: Select Simulation Date and Time

Similarly Stop date and time for the simulation is also set following the same procedures applicable to Start date and time. Now select and expand the TimeStep row.

In the Unit row the GSSF operator can select the unit in which the timestep will be entered and the read-only rows shows the maximum and minimum range of values for the given units. Finally in the Value row enter the TimeStep values.


Figure 12: Set Simulation TimeStep

Starting a Simulation After setting the Simulation Start Time, Stop Time, and Time Step, the user can run the Simulation by selecting the simulation node, click the right mouse button and select “Run” from the context menu as shown below.

Figure 13: Simulation Start-Up

In case a simulation is not saved, the GSSF user will be prompted to save the simulation file before running the simulation.

In the Runtime Controller panel, displays the job indicating the current running simulation. The user can "Continue", "Pause", "Abort" and "Delete" the Simulation job as and when required.


Figure 14: Runtime Control Panel

Pausing and Resuming a Simulation As mentioned in Section Starting a Simulation the GSSF user's can click on “Pause” button to pause the simulation and resume a paused simulation by clicking on the “Continue” button at any point of simulation time.

Terminating a Simulation Early GSSF Users can terminate a simulation at early stages by clicking on the "Abort" button. (This will stop the simulation process and disconnect the simulation from the Runtime Environment.)

Scheduling Simulation – Batch Mode GSSF can schedule simulations in Batch mode. The instruction given below will provide walkthrough on how to schedule and run simulation. (NOTE: Simulation must be loaded into GSSF, prior to setting time for scheduling). Select the Simulation node in simulation explorer view and click the right mouse button. In the context menu, select "Schedule…"

Figure 15: Schedule Simulation


A "JobInput" dialogue with JobName, Job File Name, Job Start Time, and Job Duration information is displayed. The GSSF user can select the month, date and time to schedule the simulation in the "Job StartTime" combo field list and press OK button.

Figure 16: Schedule Simulation Settings

This schedule's the simulation and the job is queued in the Runtime Controller to run at scheduled time. Similarly, the above-mentioned process is repeated for all the loaded simulation.

Please note that the user needs to activate the Batch Mode functionality by selecting in the “Runtime” menu “Batch Start”. Only with this action the simulation(s) will start automatically.

In order to be able to select the Batch Start command the RuntimeController window has to be selected.

Figure 17: To Activate Batch mode

In GSSF, user's can also save the schedule in a "*. batch" file. This process later will help to run the simulation without loading them into GSSF. In the "Runtime" menu, navigate to "Batch Save..".


Figure 18: To Save Batch File

A "Save As" dialogue window is displayed. Select the location and enter the desired name in the "File name" field and press the Save button.

Figure 19: Location to Save Batch File

In a new instance of GSSF, the user can load the batch file by navigating to "Runtime Batch Open".

Figure 20: Open Batch File


A "File Open" dialogue window is displayed. Select the file and click the Open button.

Figure 21: Locate to Open Batch File

All the jobs in the batch file will be queued in the Runtime Controller to run at scheduled time automatically.

Figure 22: Scheduled Simulation in RunTime Controller

Please note that the user needs to activate the Batch Mode functionality by selecting in the “Runtime” menu “Batch Start”. Only with this action the simulation(s) will start automatically.

In order to be able to select the Batch Start command the RuntimeController window has to be selected.


Figure 23: To Activate Batch mode

The scheduled job can be loaded into GSSF simulation explorer by selecting the respective job in Runtime Controller and clicking the right mouse button and select "Open Job Simulation" in context menu.

Figure 24: Open Simulation from Run Time Controller

Changing Parameter Values at Run-Time GSSF User’s can view data and edit parameters during Run-Time, which are not part of default simulation parameters using Alpha-Numeric Display (AND) and also visualise real time graphical plots using Graphic Display (GRD) component in the Run Time Controller. GSSF User’s can have multiple AND(s) and GRD(s) during simulation by selecting the Runtime menu and navigating to “Alphanumeric Display New…” and “Graphical Display New…” buttons. All the parameters can be added to AND or GRD by dragging and dropping them from Simulation explorer. (Note: Some parameters cannot be changed during Run-Time and when the user tries to drag'n'drop such parameters, a cursor is displayed with following

symbol ).


Figure 25: Alphanumeric Display

The AND component provides a combo box with a set of predefined units listed for parameters that users can select. All values can be changed by clicking on the respective parameters and by keying in the desired values. The GRD component provides a feature that can save graphical plots in “xxx.jpg” or “xxx.bmp” or “xxx.dib” image format. This feature is accessible via the menu Runtime Graphical Display Save.


Figure 26: Graphical Display

Generating a Simulation Report Select the respective simulation node to generate Simulation Report and click the right mouse button and select option “View Report” in the context menu as show below.


Figure 27: View Report

This will display a "Report Properties" dialogue and user can select the file type of report by selection the respective check box and click on the OK button.

Figure 28: View Report Properties

An example Simulation Report is shown below. Note summary report match's information available from the respective Summary page in the GSSF MMI.


Figure 29: Example Simulation Report

Simulation report can also be generated by clicking on the "Generate Report" button on Simulation Summary window. The only difference being that report is displayed in a new window ,instead of the center of the workspace .

Figure 30: Generate Report

GSSF users, can get a detailed text report on each component of simulation by clicking on the "Details…" link on the simulation summary page.


Figure 31: Text Report

46 • Chapter 5: Configure Timeline What do you want to simulate today? Using GSSF

Chapter 5: Configure Timeline

The Timeline is feature provides capability that allows for dynamic scenario definition (such as failures). Timeline Component can be included in simulation by selecting Simulation node and click right mouse button, navigate through Add Timeline.

Figure 1: Add Timeline

A "Select a Timeline Type" dialogue is displayed. Select "Empty Timeline" to create a new timeline component. Click the "OK" button.

What do you want to simulate today? Using GSSF Chapter 5: Configure Timeline • 47

Figure 2: Timeline Selection

In case the GSSF user wants to load a previously saved " *. time "timeline configurations file select "Existing Timeline". Click the "OK" button. A "Open Timeline" window is displayed. Select the appropriate file and click the "Open" button.

Figure 3: Open Timeline

The Timeline component consists of the Failure Event, Change Property Value and Run Function. All these function can be set to trigger changes to the simulation parameters, for given time and duration of the simulation by setting the respective values in the property grid of the corresponding functions.

The Failure and Change Property Value function can be used to trigger a Feared Events, applicable for RDG simulation. Similarly Failure function can be used to trigger failures in SVS Simulation. The Run function executes script from the given script file.

Note: Feared Events are part of the timeline component.


A comprehensive list of available Feared Events and information on how they are implemented is provided in RD 1. A table with detailed path of elements to be selected for triggering feared events is listed below.

The Change Property Value function can be used to change the values of certain parameters during run time. Select Timeline node click the right mouse button and navigate through Add Event Change Property Value as shown below to add Change Property Value.

Figure 4: Change Property Value

A "Select Change Value Event" dialogue with list of components in the simulation is displayed and the user has to select the component in left pane and the respective element from right pane, whose value shall change at specified time and for a specified duration.

Specifying Feared Events


Figure 5: Select Change Value Event

The value and the duration and repeat cycles can be set in the property grid of the respective function (e.g.: Health of the given satellite at end of its lifetime).

Figure 6: Change Value Event Properties

To initiate a Failure select timeline node and click the right mouse button and navigate through "Add Event Failure" as shown below.

Specifying Failures


Figure 7: Failure Event

A "Select Element" dialogue with list of components in the simulation is displayed and the user has to select the component in left pane and the respective element from right pane, whose value shall change at specified time and for a specified duration.

Figure 8: Select Failure Element

All the parameter such as Time, RecurrenceTime, Repeats, Duration are set in the property grid of the respective Failure Event.Once


Figure 9: Failure Event Properties

"Run Function" is another element of the Timeline. This function is useful to trigger script-based functions from script files attached to script engine of a simulation. Select Timeline node, click the right mouse button and navigate through "Add Event Run Function" as shown below to add Run Function.

Figure 10: Run Function

The Time, Duration, RecurrenceTime and ScriptExpression for the event can be set in the property grid. The Run Function Event displays all the functions available in the script files attached to the script engine of the respective simulation.

Specifiying Script Execution


Figure 11: Run Function Properties

(Note: In order to have full functionality of Run Function Event a Script Engine with a Script file is needed.)

What do you want to simulate today? Using GSSF Chapter 6: Configure Scenario • 53

Chapter 6: Configure Scenario

Creating a New Scenario A new Scenario can be added to the Simulation. Select the simulation node and click the right mouse button and select "Add Scenario" from the context menu as show below.

Figure 1: Add Scenario

A "Select a Scenario Type" dialogue is displayed prompting the user to select the desired Scenario.

54 • Chapter 6: Configure Scenario What do you want to simulate today? Using GSSF

Figure 2: Scenario Type Selection

Click the OK button to add the Scenario.

Selecting "Existing Scenario" will prompt the user to select previously saved scenario "xxx.xsco" file.

"Empty Scenario" will have an environment segment without any space, user or ground segment.

"Reference Scenario" will have an environment segment with predefined space, user or ground segment. Please note that only the machine administrator is allowed to modify the reference scenarios.

Editing a Scenario A Scenario can be edited based on user requirements by adding or removing elements. Change the properties in the property grid by selecting the elements. In the context menu select "Delete" to remove any element from the Scenario or select "Add [Type]" to add "Space Segment", "User Segment" and "Ground Segment" as shown below.


Figure 3: Scenario Segment Selection

The Space, User and Ground Segments can now be populated, again via context menu of the corresponding node to add Satellite Constellations, User Grid and Ground Station Networks. Browse functionality is also available in context menu for each segment. In case of the Space Segment, apart from Galileo and GPS constellation a wizard-based support is available to define new constellation.

It is possible to select Models (and Algorithms as part of those models) for a certain element in the Simulation explorer. If the user selects for example a Galileo Satellite in the explorer, the property grid will show the associated properties including the model currently attached. The user can change this model, by selecting the field "Value" of "Property" category in the property grid and selecting the model needed from the combo list box as indicated below.

Figure 4: Model Selection in Property Grid

Selecting Models and Algorithms


Defining a New Space Segment The Space Segment provides Galileo and GPS constellation and similarly wizard-based support available for new constellations. User’s can similarly delete or add Space Segment elements based on their needs. The Scenario can be edited and saved as per instruction give below.

NOTE: This is not applicable for EGNOS and GLONASS attributed due to the number of satellites and non-constellation based approach.

Select the Scenario node and clicking the right mouse button and navigate through "Add Space Segment" in the context menu to add a new Space Segment.

Figure 5: Add a Space Segment

Select the "Space Segment" node and click the right mouse button. Navigate through "Add [Type]" Constellation in the context menu. [Type] can be Galileo, GPS or EGNOS constellation.

Figure 6: Add Constellation to Space Segment


Selecting either Galileo, GPS or EGNOS Constellation for Space Segment launches the constellation wizard, which creates the appropriate constellation automatically with predefined inputs.

On selecting the "User Defined Constellation", a "Select a UserDefinedConstellation Type" dialogue window pops up.

Selecting "Empty Constellation" will create a Constellation without any satellites. The user has to enter the number of satellites needed and configure them individually. This includes also setting of the individual PRN numbers for the satellites.

Selecting "Walker Constellation" will open the Walker Wizard and create a walker constellation.

Selecting "Constellation File Wizard" will open a window to select the file for defining the constellation parameters.

Figure 7: Satellite Constellation Selection

Step 1: Start Walker Wizard by selecting the Space Segment node in Simulation explorer and click the right mouse button and navigating to "Add User Defined Constellation". A dialogue box is displayed with list of constellation type available. Select "Walker Wizard" and click OK button.

Walker Wizard



Step 2: Walker Wizard introduction page is displayed. Click "Next" to proceed.

Figure 9: Step 1 of Walker Wizard

Step 3: Enter the seed satellite parameters for creating the seed satellite of the constellation. Click "Next" to proceed



Step 4: Enter the Walker parameters for creating the Walker Constellation. Click "Next" to proceed.


Step 5: The name and summary of the constellation is displayed (Enter the name for constellation) and Click on "Finish" button to create the constellation under space segment.



Step 1: Start Constellation File Wizard by selecting the Space Segment node in Simulation explorer and click the right mouse button and navigating to "Add User Defined Constellation". A "Select UserDefined Constellation Type" dialogue box is displayed with list of constellation type available. Select "Constellation file wizard" and click OK button.


Step 2: The user will be provided with basic information dialogue. Click on “Select” to proceed.

Constellation File Wizard.


Figure 14: Satellite Constellation File Wizard

Step 3: A "Select Constellation File" dialogue is displayed. The user can select the suitable constellation file to create the constellation. The "Files of Type" text box helps to select the type of constellation file imported (E.g.: YUMA, and TLE). Click on "Open" button.

Figure 15: Satellite Constellation File Selection

In the Simulation explorer, the user can access elements that are contained within the Space segment. Properties are again accessible via the property grid for each element selected in the Simulation explorer.

Step 1: Start Constellation File Wizard by selecting the Space Segment node in Simulation explorer and click the right mouse button and navigating to "Add User Defined Constellation". A "Select UserDefinedConstellation Type" dialogue box is displayed with list of constellation type available. Select "Empty Constellation" and click OK button.

Empty Constellation



Step 2: A User Defined Constellation node is added to the Space Segment. Select the node and in the property grid, the user can type the desired name for the constellation and number of satellites.

Figure 17: User Defined Constellation Properties

Step 3: Based on the input the satellites are included to the constellation and by default all the satellites are Galileo.


Figure 18: User Defined Satellite Constellation

The user can change the satellite type and assign all the basic orbital parameters for each satellite in the property grid.

Figure 19: Satellite Parameters


Defining a New User Segment Select the Scenario node, click the right mouse button and navigate through "Add User Segment" in the context menu to add a new User Segment.

Figure 20: Add User Segment

Now select the User Segment node, click the right mouse button and navigate through "Add Static User" to add a Static User Receiver.

Figure 21: Add Static User

Similarly a User Grid can be added to the user segment container by selecting the node, clicking the right mouse button and navigate through "Add User Grid", as show below.


Figure 22: Add User Grid

Select the respective component and scroll through the property grid on the right side; the user can edit the values as appropriate for the Simulation as shown below.

Figure 23: User Grid Properties

Similarly the operator can add a grid for Service Analysis by selecting the Static User node and navigate through "Add Service User Grid" in the context menu.


Figure 24: Add Service User Grid

In the property grid of "Service User Grid", in addition to geographical position and resolution has other parameters such as Availability, Combination, Random Selection, and Threshold. These parameters can be set to cause random failures and its combination, during a check for critical satellites. Similarly threshold limits for computing protection level and navigation system precision can also be specified.

Service Grid is used to run the following analyses.

• Global or Regional Availability of Service

• Global or Regional Critical Satellites

• Global or Regional Availability of NSP with failures

• Global or Regional Availability of Integrity with failures


Figure 25: Service User Grid Properties

GSSF provides look up table to enter, load and save UERE configuration and load, them as single UERE files.

Note: GSSF provides a set of predefined UERE tables as part of installation. These tables are based on UERE budget definition specified in APPENDIX A to this document of the Service Volume Reference Scenario.

Configure UERE for User Receiver


Select the User Receiver node, click right mouse button and navigate to 'Configure UERE…' from the context menu. GSSF scan’s for available UERE table in the ‘UERE Budgets’ folder of GSSF installtion directory.

Figure 26: Configure UERE

A 'Configure UERE Budget' table is displayed with two panes for Galileo and GPS constellation. The combo box lists UERE tables available in the UERE Budget Folder of GSSF installation.

Figure 27: UERE Look Up Table

Click on the pointed arrow button of combo box and select the required table. The corresponding name and description of selected UERE table is displayed in the respective fields. Click ‘OK’ to load the selected UERE table.

GSSF users can create UERE tables by clicking ‘NEW’ button. The name, description and grid table is switched to edit mode. Now the user can enter a suitable name, description and UERE values required.


Figure 28: Create UERE Budget Table

Once the UERE values are entered, the user can save the respective table by clicking 'Save' button. A 'Save UERE Budget' dialogue is displayed to select location to save the file. Click on the ‘Save’ button to the save the file.

Figure 29: Save UERE File

Similarly, the users can load UERE file by clicking the 'Load' button. A ‘Load UERE Budget’ dialogue is displayed. Now select the required UERE file and click ‘Open’ to load the file.


Figure 30: Load UERE File

Every scenario element that contains a UERE computation model also provides a property in order to configure a UERE margin (‘UEREmargin’). The UERE margin is applicable to the UERE budget that is used for the protection level (integrity) computation. For NSP computation it doesn’t have an impact. Thus both computations, protection level and NSP, are based on the same UERE table, were as the protection level computation applies a margin to the UERE budget.

Defining a New Ground Segment

Ground Segment can be added to a Scenario by clicking right mouse button and navigate through "Add Ground Segment" in the context menu.

Figure 31: Add Ground Segment


A Ground Network can be added to the Ground segment by clicking the right mouse button and navigate through "Add Ground Network".

Figure 32: Add Ground Network

A "Select a GroundNetwork Type" dialogue with set of predefined "GSS","TTC","ULS" and "GSTB-V1 GSS Sites" and "Empty Station Network" is displayed. Select the desired station network and press OK button.

Figure 33: Ground Network Selection

GSS, is a network of Galileo Sensor Stations.TTC, is a network of Telemetry Tracking and Control Stations, ULS is a network of Up Link Stations and GSTB-V1 GSS Sites, consist of Galileo System Test Bed - GSS Stations

In order to add one or more Galileo Sensor Stations to the Ground Segment. Select Ground Segment node, click the right mouse button and navigate to "Add Ground Station GSS Stations".


Figure 34: Add Galileo Sensor Stations

A selection box appears where the stations (e.g. KOUR) to be simulated have to be selected.

Figure 40: Select Galileo Sensor Station

Once the station is added to the Ground Segment Node the receiver channels have to be configured. This has to be done through the “Signal Tracking” property.


Figure 41 Configure Signal Tracking

In the property grid the channels that have to be simulated must be set to true (e.g. Galileo.E6A).


Figure 42: Channel Selections


Generating a Scenario Report Select the respective scenario node to generate Scenario Report and click the right mouse button and select option “View Report” in the context menu as show below.

Figure 43: View Scenario Report


Figure 44: Scenario Report Properties

The Scenario Report is displayed in the centre window of the GSSF workspace as shown below.


Figure 45: Example Scenario Report

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Chapter 7: Analysing Data

GSSF offers predefined analyses to the user. For on overview on the currently available analyses please refer to Section Simulation and Analysis Capabilities. For information on which analyses are applicable to SVS or RDG, please refer to section Analyses that are Applicable to GSSF SVS and Analyses that are Applicable to GSSF RDG . A detailed definition and description including information on input/output data sets can be found in RD 1

Selecting/Editing Analyses As part of the Simulation, the user can select analyses that are to be performed.

Select the Analyses node click the right mouse button and select "Add Analysis" in the context menu, the user can select the type of Analysis as illustrated below.

Figure 1: Add Analysis

A "Select Analysis" dialogue window appears with list of available Analysis. The user should select analyses that are appropriate for the type of simulation.

78 • Chapter 7: Analysing Data What do you want to simulate today? Using GSSF

Figure 2: Analysis Catalogue

Once the user has selected the analysis click the OK button, the analysis is visible in the simulation explorer as shown below.

Figure 3: Analysis in Simulation Explorer

On selecting the Analysis node in the simulation explorer, the properties of an analysis become visible and accessible in the property grid.


Figure 4: Analysis Properties

Please note that when selecting pre-defined analysis the system automatically detects which data is necessary in order to perform this analysis. The data will be automatically recorded by an internal recording facility, which has a pre-defined setup. The data is recorded in binary format. The different binary formats are described in APPENDIX C. Later XML files are created by the post-processing facilities in order to be used for analysis. The XML data files follow the format of the ADO.NET Dataset.

However there are limitations on the amount of data that can be processed inside the machine’s memory. For that reason GSSF has a feature that automatically switches to a “Streamed” data processing mode when the amount of recorded data is above a certain limit. The current threshold is 5 Mbyte (binary data per file), but can be changed by the user. Every analysis component provides a property ‘ProcessingThreshold’ in order to adjust the amount of binary data that gets processed in memory.

In the “Streamed” mode data is not loaded into memory and therefore not accessible by the user, i.e. no raw data and no visualization can be accessed. However all analysis support this “Streamed” mode and can run and produce results without any problems.

As said above, if the amount of recorded data is too big (> 100 MB binary), there are problems in loading them into memory, and therefore to use them (process, display).

The maximum size of the binary recorder file that still can be handled by a standard machine with 1 GByte of memory was analysed. It was used the ‘Global or Regional NSP’ analysis for that and set the processing method to


'InMemory'. The analysis was performed on a nominal Galileo constellation with a 5 deg user world grid.

The table below lists the results. Simulation

Period [days] Recorder File Size

[MByte] In-memory processing

possible

2 48 Yes

3 71 Yes

4 94 No

So the conslusion is that a binary file with a size of 94 MB and above has problems in processing the recorded results "InMemory".

Please note that the problems with the in-memory processing of data have no impact on the computation of the different figures of merits and other statistical results that the system provides. A problem related to in-memory processing of recorded data only avoids visualizing and user-driven processing of the raw binary data. This is currently a limitation of the system, but does not prevent analysing the performance of GNSS, such as Galileo or GPS.

Defining Analysis Parameters In the property grid of Analysis various parameters are set and the following sections will describe them in detail.

Once Analyses is added to the Simulation explorer, the user has to select the elements that are to be analyzed. GSSF prompts the user to select the elements to be analyzed before including the Analysis node to the simulation explorer. In case if the user wants to select the elements at later stage the following section explains the same.

Select the Analysis node in simulation explorer and in the property grid select the row "Elements" as shown below. Click on the ellipse button in the extreme right to assign the element to be Analysis of the simulation.

Selecting Elements - Analysis


Figure 5: Define Element for Analysis

On clicking the button, a "Select Elements" dialogue pops up and lists all the simulation elements as show. Select the required elements from the list and press OK button. This adds the elements to the Analysis (Note: Elements only suitable for the respective Analysis is displayed).

Figure 6: Select Elements for Analysis

On selecting an Analysis from the Simulation Explorer, a Property Grid is displayed on the right side with a explorer of parameters listed for the associated Analyses. This provides the user with option to set the AutoRun, Elements, UpdateRate, Filter Constellation, Elements, Filter Region, Filter

Define Analysis Control Parameters


Time etc. All these parameters should be set before starting a simulation or processing the recorded simulation data.

Figure 7: Define Analysis Control Parameters

AutoRun feature, when set to 'True' will run the Analysis once the simulation is completed and process the recorded data.

Elements feature contains pre-selected simulation elements on which analysis is to be performed and GSSF users can edit them if required.

Update Rate feature sets the Progress status update rate (in %) for progress bar, while processing the data.

Filter Constellation feature will filter the data recorded pertaining to the selected constellation, while processing the data.

Filter Region feature will help user to select specific region and its limits in terms of Latitude and Longitude for processing data.

Filter Time feature will process only the data recorded for the given time range selected.

Please refer to the GSSF Operations Manual Volume 2 (GSSFP2.OM.002) for additional properties of the specific analyses.


Executing Analysis After running the simulation the analysis is processed automatically without user interaction. However if GSSF user wants to analyse the pre recorded simulation data after changing settings like "FilterRegion","FilterTime","UpdateRate", "AlertLimits", and "Threshold", the following section explains the same.

Select Analysis node from the Simulation explorer, click the right mouse button and navigate to Analysis Run in the context menu.

Figure 8: Run Analysis

This will process the recorded data and will start attached visualisation automatically, based on Analysis selected. This feature will automate the process of visualising the processed data.

Defining Output-Data Visualisations GSSF, by default has Visualisation attached to Analysis that is deemed appropriate for the type of analysis to be performed. However, if the user wishes to have additional or different visualisation option it can be done as mentioned below.

Select the analysis node, click the right mouse button and navigate to "Add Visualisation" to attach visualisation for given analysis.


Figure 9: Add Visualisation to Analysis

A "Select Visualisation" dialogue box will list the type of visualisation as shown below.

Figure 10: Visualisation Catalogue

GSSF user, need to select appropriate visualisation for given Analysis and click "OK" button. Note: Visualisation can be attached before processing the recorded data or after processing the data, but not in due process.

Apply Mathematical function to Processed Data GSSF, as part of enhanced data management provides function to process data by appyling Mathematical, Trignometric and Statistical functions. The instruction given below will guide you in processing the required data.


In the Data Storage explorer view, select the data to be processed and click the right mouse button. In the context menu, select 'Process'.

Figure 11: Process Data

A 'DataProcessorView' widget tab window is displayed in the center of GSSF workspace. In the combo box labelled 'Operations', select the type of operations to be perfomed. (Note: in some cases, another combo box labelled 'Units' is displayed appropriately to facilitate data processing in different units.)


Figure 12: Data Processor View Window

Select the 'Data Table' and 'Data Column' from respective combo box and click on 'Add Couple' button.

Figure 13: Data Processor Option - Selection


Now click on 'Process' button to process and apply the function for selected data column. Expand the explorer node in the data sheet view window and click on the applied function name to view the processed result.

Figure 14: Processed Data Result

The users can store the processed result by clicking on the 'Save Result' button. A new folder named 'Processing' added to the data storage and the results are stored in this folder.

Figure 15: Processed Data Result in Data Storage


Comparing Data In GSSF, data storage area users can compare data with another data set.

Select the dataset in data storage area and click right mouse button. In the context menu select 'Select Left Side to Compare'.

Figure 16: Select Data to Compare

Now select another dataset you wanted to compare with and click the right mouse button. In the context menu, select ' Compare to "<previosuly selected dataset name>"'

Figure 17: Select Data to be Compared

A 'ComparisionManagerView' tab window is displayed in the center of the GSSF workspace.


Figure 18: Comparison Manager View Window

Select the table and the respective column for both the data set in the combo list box. Click the 'Compare' button.

Figure 19: Select Table and Column to be Compared

In the data sheet view, expand the explorer node to get the difference between the two compared columns.


Figure 20: Compared Data Result

The users can store the compared result by clicking on the 'Save Result' button. A new folder named 'Comparisons' added to the data storage and the results are stored in this folder.

Figure 21: Newly Saved Compared Result

Extracting Grid Data GSSF, provides feature to extract recorded and analysed data for a given user receiver in a grid. The GSSF operator has to select the given dataset, from which the data has to be extracted and click the right mouse button.

In the context menu select "Extract Grid Point".


Figure 22: Extract Grid Point

A Extract Grid Point dialogue is displayed. A list of tables in the selected dataset is displayed in the left pane and option to enter the co-ordinates of the grid point in Latitude and Longitude is provided.

Select the Table from which the data is to be extracted and enter the co-ordinates of grid point. Click on the OK button.

Figure 23: Extract Grid Point Dialogue

The selected data is extracted and saved in the same dataset file as a separate table and is listed in the data tree. Click on the extracted tree to view the extracted data.


Figure 24: Extract Grid Data

RAMS Support in GSSF Three distinct classes of use for RAMS analysis within Galileo system design can be identified:

• "Traditional" RAMS Analysis: The system is modelled as chains of "Reliability Blocks" with specified reliability parameters such as Mean Time Between Failures (MTBF) or Mean Time To Repair (MTTR) in order to verify that system-wide equipment RAMS requirements are met.

• “Availability of Service Analysis”: This is subtly different from Case 1 and considers running a Service Volume Simulation for parameters, such as position accuracy, and calculating the availability taking satellite failures into account.

• "Feared Events" Analysis: This implies modelling the impact of Feared Events (FE) on user-level performance.

GSSF is not designed specifically for above class 1 while support to class 3 is limited to the scope of FEs implemented in RDG (see RD 1). However, GSSF V2.0 provides Availability of Service Analysis subject to deterministic or randomly selected Satellite Failure cases. This analysis is defined in detail in RD 1. Please refer to Section Simulation and Analysis Capabilities for individual Figures of Merit evaluated by the Service Availability Analysis.

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Chapter 8: Visualising Data

Visualising Data on Time Plots A 2D Time Plot of high resolution can be viewed once Simulation is completed and the results for the respective Analysis are processed. This can be done in two ways: Attaching the respective Visualisation to the Analysis directly by selecting the Analysis node and clicking the right mouse button and navigating through "Add Visualisation" in the context menu.(Note: GSSF users, should remove the default visualisation attached to Analysis)


The above process will launch the "Select Visualisation" dialogue with all visualisation options including TimePlot component.

94 • Chapter 8: Visualising Data What do you want to simulate today? Using GSSF

Figure 2: Visualisation Type Selection

The user should select the TimePlot from the dialogue window and click OK button. This generates a respective Time Plot node as sub-node of the analysis. In the property grid of the visualisation on the right-hand side the user needs to configure the visualisation.


Figure 3: Time Plot Visualisation Configuration

After processing the recorded simulation data by the analysis the attached TimePlot will be displayed in the centre of the workspace. The GSSF operator has to select the "DataTable", which forms the source of elements in "DataColumn" to be displayed. At present GSSF TimePlot supports six DataColumns.This feature plot the multiple data in layers (e.g.: Elevation, Azimuth, and Doppler).

The second approach is to use processed data sets directly. By selecting the corresponding data set in the data storage and click the right mouse button select Visualise in the context menu.


Figure 4: Time Plot Data Set Selection

This launches the "Select Visualisation" dialogue with TimePlot component and the user should select the Time Plot from the dialogue window. This generates a respective Time Plot window in the centre of workspace. Using the property grid of the visualisation window on the right-hand side the user should configure the visualisation.


Figure 5: Time Plot Visualisation Configuration

Figure 6: Time Plot


Visualising Data on Map Plots A Map Plot of high resolution can be viewed once Simulation is completed and the results for the respective Analysis are processed. This can be done in two ways: Attaching the respective Visualisation to the Analysis directly by selecting the Analysis node and clicking the right mouse button and navigating through "Add Visualisation" in the context menu.(Note: GSSF users, should remove the default visualisation attached to Analysis)


The above process will launch the "Select Visualisation" dialogue with all visualisation options including Map component.



The user should select the Map from the dialogue window and click OK button. This generates a respective Map Plot node as sub-node of the analysis. In the property grid of the visualisation on the right-hand side the user needs to configure the visualisation.


Figure 9: Map Plot Visualisation Configuration

After processing the recorded simulation data by the analysis the attached Map will be displayed in the centre of the workspace. The GSSF operator has to select the "DataTable", which forms the source of elements in "DataColumn" to be displayed.



Figure 10: Map Plot Data Set Selection

This launches the "Select Visualisation" dialogue with Map component and the user should select the Map Plot from the dialogue window. This generates a respective Time Plot window in the centre of workspace. Using the property grid of the visualisation window on the right-hand side the user should configure the visualisation.


Figure 11: Map Plot Visualisation Configuration

ColorPalette: This specifies the type of colour range used to display the map.

ColourBarMin and Max: The range of colour bar with option to select the minimum and maximum values to show the results explicitly for given range.


ShowFrameSelector: If set True displays a Frame slider, which can be scrolled across to display the results at any given point of Simulation.

Resampling: The resampling option interpolates the grid point to reduce distortion of the map plot.

Figure 12: Map Plot


Visualising Data on Radar Plots A Radar or Sky Plot of high resolution can be viewed once Simulation is completed and the results for the respective Analyses are processed. This can be done in two ways: Attaching the respective Visualisation to the Analysis directly by selecting the Analysis node and clicking the right mouse button and navigating through "Add Visualisation" in the context menu.(Note: GSSF users, should remove the default visualisation attached to Analysis)


The above process will launch the "Select Visualisation" dialogue with all visualisation options including RadarPlot component.



The user should select the RadarPlot from the dialogue window and click OK button. This generates a respective Radar Plot node as sub-node of the analysis. In the property grid of the visualisation on the right-hand side the user needs to configure the visualisation.

Figure 15: Radar Plot Visualisation Configuration

After simulation this will display the time plot in the centre of the MMI.



Figure 16: Radar Plot Data Set Selection

This launches the "Select Visualisation" dialogue with RadarPlot component and the user should select the Radar Plot from the dialogue window. This generates a respective Time Plot window in the centre of workspace. Using the property grid of the visualisation window on the right-hand side the user should configure the visualisation.

Figure 17: Radar Plot Visualisation Configuration


Figure 18: Radar Plot

Visualising Data on Pair Plots A Pair Plot of can be viewed once Simulation is completed and the results for the respective Analyses are processed. This can be done in two ways: Attaching the respective Visualisation to the Analysis directly by selecting the Analysis node and clicking the right mouse button and navigating through "Add Visualisation" in the context menu.(Note: GSSF users, should remove the default visualisation attached to Analysis)



The above process will launch the "Select Visualisation" dialogue with all visualisation options including PairPlot component.


The user should select the PairPlot from the dialogue window and click OK button. This generates a respective Pair Plot node as sub-node of the analysis. In the property grid of the visualisation on the right-hand side the user needs to configure the visualisation.

Figure 21: Pair Plot Visualisation Configuration

After simulation this will display the pair plot in the centre of the MMI.



Figure 22: Pair Plot Data Set Selection

This launches the "Select Visualisation" dialogue with PairPlot component and the user should select the Pair Plot from the dialogue window. This generates a respective Time Plot window in the centre of workspace. Using the property grid of the visualisation window on the right-hand side the user should configure the visualisation.

Figure 23: Pair Plot Visualisation Configuration


Figure 24: Pair Plot

Visualising Data on Stanford Plots A Stanford Plot of can be viewed once Simulation is completed and the results for the respective Analyses are processed. This can be done in two ways: Attaching the respective Visualisation to the Analysis directly by selecting the Analysis node and clicking the right mouse button and navigating through "Add Visualisation" in the context menu.(Note: GSSF users, should remove the default visualisation attached to Analysis)



The above process will launch the "Select Visualisation" dialogue with all visualisation options including StanfordPlot component.


The user should select the StanfordPlot from the dialogue window and click OK button. This generates a respective Stanford Plot node as sub-node of the analysis. In the property grid of the visualisation on the right-hand side the user needs to configure the visualisation.


Figure 27: Stanford Plot Visualisation Configuration

After simulation this will display the Stanford plot in the centre of the MMI.


Figure 28: Stanford Plot Data Set Selection

This launches the "Select Visualisation" dialogue with StanfordPlot component and the user should select the Stanford Plot from the dialogue window. This generates a respective Time Plot window in the centre of workspace. Using the property grid of the visualisation window on the right-hand side the user should configure the visualisation.


Figure 29: Stanford Plot Visualisation Configuration

Figure 30: Stanford Plot

Saving Visualisations GSSF is able to save visualisations of processed simulation output or analysis results to hard disk. This can be done following the steps given below.

Step 1: Visualise data. For more details see sections above (section Visualising Data on Time Plots or Visualising Data on Map Plots) or the tutorial’s section (section Tutorial 1: Analysing Global Availability of Integrity or Tutorial 2: Analysing Global Dilution of Precision).

Step 2: Select Tools Export Graphic.


Step 3: A Save File dialogue is displayed. Enter a name for the image in the File Name text box.

Step 4: Select format of graphics to be exported: Bitmap (.bmp), Windows Metafile (.wmf) or JPEG (.jpg)

Step 5: Click the Save button.

Via browsing the corresponding directory of the hard disk, the user can verify that the visualisation have been exported and written to hard disk.

Visualising Saved Data GSSF has the ability to retrieve processed data in XML data sets and visualise them. This can be done by loading a data storage file, which contains processed data. Then proceed with visualisation of the contents of the data sets as described in the sections Visualising Data on Time Plots or Visualising Data on Map Plots.

In future it will be possible to associate a visualisation with a dedicated external file that contains the data to be visualised. The following steps will guide you through this process.

Select the Visualisation node in the simulation explorer view and click the right mouse button and navigate through "Add Visualisation".

Figure 31: Add Visualisation

This will display a "Select Visualisation" dialogue listing the available types of visualisations. Select the type of visualisation and click the OK button.


Figure 32: Select Visualisation

Now in the property grid of the selected visualisation, set "Use External File" row to True and Select "Data File Name" row click on the "…" button on the right side.

Figure 33: Visualisation Properties Configuration

A "File Open" dialogue window, where the corresponding data file can be selected in order to visualise the saved data.


Figure 34: Open File for Visualisation

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Chapter 9: Modelling in GSSF

GSSF and Modelling In GSSF V2.0, models are view as components. The implementation of the models is the most valuable part of the models. Therefore, we want to maximise the potential for reuse of these implementations. For this reason we want these models to be as platform-independent as possible. Considering requirements for real-time behaviour of the models, the default language for the models is currently C++. Further, we need to isolate the modellers from the underlying complexity of the infrastructure. Finally, depending on the type of integration required between models and the simulation environment, we need to have integration mechanisms like SMI in order for these models to communicate with the simulation environment.

Modelling Capabilities in GSSF The GSSF MDE automatically generates the C++ Wrapper class (inherits the model behaviour from the Inner Class), which includes functionality such as loading of models, and store/restore. This wrapper class will also implement the Software Model Interface (SMI) publication function. The C++ Inner Class (model implementation) contains methods, fields and properties strictly required for modelling, the MDE only generates a skeleton structure of this class leaving the methods empty and ready to be implemented by the modeller. Using this layout means the modellers do not need any in depth knowledge of how the simulator infrastructure operates. In addition to the generated C++ source code, the MDE will automatically generate three Visual Studio .NET (V7.0) projects:

• Model project, which includes all the necessary files (e.g. C++ headers and bodies) to build the model;

• CppUnit test fixture project, providing a starting point to implement unit tests for your model;

• CppUnit runner project, providing a console application, which invokes the test methods in your test fixture

In order to manage the large number of models GSSF requires both for End-to-End (ETE) and Service Volume Simulation (SVS), we need a way of defining all the types and interfaces and making sure these are coherent with respect to each other. The approach we have chosen allows us to “compile” these type definitions (i.e. interfaces, classes, enumerated types and structures). In this section, we will describe how this process works.

While defining the types, which captures the contracts between the different models, we want to construct a unique source of data, containing:

• Methods signature

• Properties

• Tunable parameters (also referred as field in this document)

An Introduction to GSSF Code Generation

Model Definition

118 • Chapter 9: Modelling in GSSF What do you want to simulate today? Using GSSF

• Documentation

• Attributes (see Section Attributes for an explanation of what attributes are)

We believe that the Models Architecture is one of the most valuable parts of GSSF. Therefore, we want to maintain this artifact in a neutral format. We have chosen XML for this, since it is clearly an emerging industry standard, is platform independant and is likely to be around for a while. Further, it is also likely that we will need to transform the XML data into other formats, in the future, if required. The other important aspect of our model architecture is that we want to be able to “compile” it, to ensure that it is valid, complete and coherent.

The process of defining a model in the MDE is the following:

• Define types (i.e. interfaces, classes, enumerated types and structures) in UML using a CASE tool capable of generating C# code. Rational XDE is used to perform this task. This step is optional as most of our work, so far, has been performed starting from Step 3.Attributes are assigned using UML LanguageAttributes in the CASE tool.

• Generate C# code from the UML model

• Create/Modify models in the C# IDE. Microsoft’s Visual Studio .NET is used to perform this task. Documentation is added in the C# source code directly, using the “///” XML documentation feature of Visual Studio .NET. The user needs to set the generation of the XML documentation, in the options of the Visual Studio project. The file name has to be set to the same name as the target assembly name with the extension “.xml”. So for example if you are compiling into the file Architecture.dll the output xml file should be Architecture.xml, this file name must be set in the Visual Studio project.

• Compile the models into a .NET assembly (i.e. DLL or executable). Verifying that the assembly is created, alongside with the Visual Studio XML documentation file.

• Generate the model catalogue using the MDE. Internally, the MDE uses reflection, a feature of C# (also supported by other languages like Java) to extract all the type information from the .NET assembly. This information is saved in XML. This XML document is the model catalogue and is therefore the springboard for several other activities in GSSF.

(In this section we use the term field, a term introduced by Microsoft in the .NET Framework. Fields are the same as for members in C++ or attributes in UML.)

Attributes are a special feature of C#. Java also supports a similar, but limited, feature. At the time of writing this document, we understand that a C# attributes feature is being investigated for Java 1.5 (this is not confirmed). This would be interesting, since it would allow modelers to eventually define models in both languages, C# and Java. Another future possibility is UML 2.0, which we hope will support “compiling” of models.

The main idea of attributes emerged at Microsoft from limitations from COM, where COM meta-data (in its IDL) was limited by the standard. In C#, attributes are simply instances of other classes, inheriting from a special attribute class. Placed between square brackets on a type, the compiler verifies that the attribute assignment is valid in the local context; this means that the meta-data is also verified and compiled. This allow us to “charge”

Attributes


normal types with a rich set of meta-data, which will be used by other GSSF components like:

• Code Generators: Attributes can be used to define code generator options this applies to such things as collections, which can be built out of a simple “Coll” attribute. Or a save and restore method implementation can be generated for all fields not marked with the “NoSerial” attribute.

• Graphical User Interface (GUI): read/write access instructs (via the “Vis” attribute) Alpha Numeric Displays (AND) and property grid in what access is to be granted to the user. Categories can also be assigned to fields to provide a useful grouping in the Infrastructure Property Grid.

• Default values: values defined by the modelers such as the mass of a satellite.

• Assembly rules: default types for children contained by parent models

The following example shows a field state of type GndElementStatus. The “///” and the XML summary element contains the description of the field (this type of description can be applied to virtually any type in C#). Visual Studio exports the summary text into a separate XML file, which can later be used to provide documentation or help files related to the code. The attribute Vis takes two parameters, indicating the end-user’s access right on this field in the Infrastructure and the category (the category is used to group properties in the property grid of the infrastructure).

/// <summary>

/// Current state of the ground element.

/// </summary>

[Vis(Visibility.ReadOnly,Category.Basic)]

GndElementStatus state;

From this rich set of meta-data and type definition, we can then generate target code for these models, i.e. the C++ inner classes. Table 3 below contains a full list of the Attributes.

Table 3 – Attributes in GSSF

Attribute Description

Coll(Type type) Indicates that this interface defines access to a static collection of elements of the same type. This means that the collection size will not change during simulation run-time, and will only be sized during the initialisation of the model.

CollClass Indicates that this is a class collection. It must realise a collection interface (i.e. an interface tagged with the 'Coll' attribute). The class must also contain a single field named 'item' of the type specified in the 'Coll' attribute of the realised collection interface.

Def(double val) This attribute defines the default value for a field or property. Useful for giving numerical default values.

Def(string val) Useful for giving default name to strings.


Def(bool val) Useful for giving true/false default value to Booleans.

Def(int val) Useful for giving integer default value to integers.

DefineGlobalNums(GlobalNums val) Indicate that this field defines the corresponding GlobalNums entry in the GlobalNums service.

DefaultType(Type type) Specifies a field's model default type. If specified, this attributes determines that the field is actually an instance of the type specified. When the class is created and loaded from file, the field will be initialised to a new instance of that type, unless the type is overriden (if PlugIn is specified, for example).

This attribute indicates that the model is a Plug-in, which means that the end-user is able to switch the model of the field this attribute is assigned to.

Range(double min, double max) This attribute indicates the range on this property or field

Reference Identifies that this field is a reference to another model or service. This field should be shown as a leaf model by the infrastructure.

Service(Services service) On a field, this attribute indicate that this field references a service. These services are the "global" objects of all GSSF simulations. Services are created before any models and live for the entire duration of the simulation.

ServiceDefinition(Services service) This attribute defines this class as a service. These services are the "global" objects of all GSSF simulations. Services are created before any models and live for the entire duration of the simulation.

Size(GlobalNums val) Definition of a single dimension array, taking a GssfAttribute.GlobalNums parameter for the size

Size(GlobalConst val) Definition of a single dimension array, taking a GssfAttribute.GlobalConst parameter for the size

Size(int val) Definition of a single dimension array, taking an integer parameter for the size

Size(GlobalConst val1,GlobalConst val2) Definition of a 2 dimension array, taking an GssfAttribute.GlobalConst parameter for the size

Size(int val1, int val2) Definition of a 2 dimension array, taking an integer parameter for the size

Unit(Units val) This attribute defines the unit of a field or property

Vis(Visibility vis, Category cat) Visibility attribute. This type is used to inform the Infrastructure on the visibility level of the corresponding property.

Wired(string name) This attribute wires a field to an interface property


Model Development Guidelines These guidelines are here to facilitate integration of models. With the right level of knowledge, these guidelines should not be seen as mandatory.

All models should be provided in source code format, complete with their full development documentation.

Models should not contain any internal scheduling mechanisms.

Each method that is to be scheduled directly by the simulation environment need to have a specific TBD signature (probably void).

Schedulable models should include the corresponding attributes definitions.

All models should only use the units defined in GSSF

GSSF will provide the following services:

• Scheduling of the model execution at the desired rate

• Interfaces to the operating system and to external systems

• Time: This is provided to the model each time it is scheduled. GSSF will also provide other times.

• Logging: Logging of messages at run-time

• File I/O: Special services are provided for disk access used for initialisation of models before the simulation starts. These services need to be used by the models for disk access and asynchronous behaviour.

For platform independence it is recommended that all model initialisation data and test data should be in ASCII format or in XML.

Models should not make any system calls at run-time (i.e. it must not make operating system calls).

Models representing equipment should include models of failures and redundancy .

Algorithmic models should be stable over a range of scheduling frequencies. The stability range should be defined with the model documentation.

All functionality of the model should be configurable at initialisation. Changes between different modes should be possible at run-time without re-initialisation of the model.

Every tuneable parameter or parameter that are of interest to the end-user, as well as the parameter required to be saved and restored should be defined in the definition stage with the appropriate attributes.

For all implementation, compilation and linking related activities relevant to GSSF model development, the Integrated Development Environment (IDE) Microsoft® Visual Studio® .NET (V7.0) is recommended. Plain model development can always be done outside GSSF. However, the plain model would have to be integrated in GSSF by means of a GSSF compatible wrapper model that can be generated with the GSSF mode development functionality. Note, Visual Studio®7.0 is necessary only for the integration task. (Tutorial 4: Modify Algorithm using GSSF describes how to develop a model and integrate into GSSF)

The Model Architecture uses a rich set of Metadata to describe a model and its Interfaces, properties and Fields. The summary information from the Architecture is even used to produce help to the end user of a model.

General Guidelines

The Model Architecture


• We recommend using Microsoft’s Visual Studio .NET to perform this task. A few basic rules are outlined here

• Documentation is added in the C# source code directly, using the “///” XML documentation feature of Visual Studio .NET. The user needs to set the generation of the XML documentation, in the options of the Visual Studio project. The file name has to be set to the same name as the target assembly name with the extension “. xml”. So for example if you are compiling into the file SvsMain.dll the output xml file should be SvsMain.xml, this file name must be set in the Visual Studio project.

• Compile the models into a .NET assembly (i.e. DLL or executable). Verifying that the assembly is created, alongside with the Visual Studio XML documentation file.

• Once the .dll and .xml files are created they can be used to create a GSSF Model Catalogue. As previously stated the outputs of these two solutions are four files is two .dll and .xml.

• Copy these four files (by default they will be placed in the bin\debug folder of the solutions) into a new empty folder. For this example we will use C:\Model \ follow the steps below to load and create the new Model Catalogue.

Start the GSSF application.

From the File menu select “Open ModelCatalogue”, as shown below.

Figure 1: Open Model Catalogue

Open the SvsMain.dll file in the C:\Model folder, GSSF will now automatically generate an. xcat file. The information in this XML catalogue is used to populate information in the property grid, provide help to the end user and to generate C++ code for model development.

Code generated by GSSF will be placed by default in a folder below one containing the .xcat file. It will be named using the namespace and model it was generated from (i.e. C:\GSSF\GssfGround.GNDOSPF). Three folders will be created under this; they will be named classname, classnameTestFixture and classnameTestRunner. Under the classname

Creating and Modifying Model definitions

Generated Code


folder will be the implementation class files named classname_impl another folder containing the generated base class can also be found here.

Figure 2: Windows Explorer Explorer

Each folder contains a Visual Studio .NET project file, each of which can be loaded and compiled under VS.NET it is recommended that you create a Solution file, which contains these three projects; the TestRunner project should be marked as the ‘Startup Project’. The diagram below shows how the generated projects are related to each other, modellers should complete the _impl classes and the CppUnit TestFixtures. Modifications to the class signature should be carried out in the C# architecture so that changes can be easily integrated with the rest of the system. The base class can then be re-generated from the new C# signature while the implementation class and test fixture signatures will need to be modified by hand. Re-generating the implementation and test classes at this time would overwrite any user-generated code contained in these model classes. The diagram below illustrates an example of the relationship between the generated classes.

GalileoSatellite GalileoSatellite_impl

GalileoSatelliteTestFixture

«Friend Permission»

«interface»IGalileoSatellite

The GalileoSatellite_impl and GalileoSatelliteTestFixture will be implemented by hand and should only be generated once.

«interface»IPayload

Payload is a child of the GalileoSatellite class

«interface»IGClock

«use»

In this example if IGClock was not a child of GalileoSatellite it could be seen as a parameter to a method.

Figure 3: Model Development Structure

GSSF supports reference counting to manage an object’s lifetime. This provides a mechanism by which an object self-destructs when all of its ‘clients’ have released their references to the object. The drawback is that incorrect reference count usage may cause objects to have references to already destroyed objects or may cause memory leaks when objects are no longer used but have not self-destructed. The GSSF implementation of reference counting is in line with the COM implementation and provides a clear roadmap to using COM compatible models.

Implementing a Model Reference Counting


From the client model’s perspective reference counting is always done for each interface. The default case is that AddRef must be called for every new interface pointer and ‘release’ must be called for every destruction of an interface pointer. Implementation of reference counting in the models should not be over complex assuming that the model code is written to a good standard.

Example of reference counting - default case

void Model_1::Method_1()

{

HRESULT hr = E_FAIL;

HRESULT status = E_FAIL;

GssfSpace::GpsSatellite *satModel;

hr = CreateInstance("GssfSpace.GpsSatellite",

"GssfSpace.IGpsSatellite",

(void **)&Model);

…

…

… model implementation

…

…

satModel->Release();

return status;

}

The call to AddRef is handled inside the generated ‘CreateInstance’ call so the only considerations for the modeller in this case is to include a ‘Release’ before returning from the method. However this can be further complicated if the code has multiple exit points, as it must release the Interface before exiting. Care must also be taken not to call release too many times as this will lead to problems for other users of an Interface.

There are a number of exceptions to the default rule when using reference counting; an example of each is included: The caller must call AddRef on the parameter because it will be released (with a call to Release) in the implementing code when the out value is stored on top of it.

When creating a local copy of an interface pointer from an existing copy of the pointer in a global variable, you must call AddRef on the local copy because another function might destroy the copy in the global variable while the local copy is still valid.

ParentModel::CopyInterface(IObject* parentModel)

{

this->model = parentModel;

this->model->AddRef();

In-out parameters to functions

Fetching a global variable


}

In this example the ParentModel class would handle the release for the local copy of the interface when it goes out of scope. For example in the destructor of the class…

ParentModel::~ParentModel()

{

this->model->Release();

}

A function that synthesizes an interface pointer using special internal knowledge rather than obtaining it from some other source must call AddRef initially on the newly synthesized pointer. Important examples of such routines include instance creation routines. For example the GSSF implementation of the ‘SwitchInterface’ (COM equivalent is IUnknown::QueryInterface) calls AddRef before returning. However this interface must be released by the calling function when the interface is no longer needed.

When a function retrieves a copy of a pointer that is stored internally by the object called, that object's code must call AddRef on the pointer before the function returns. Once the pointer has been retrieved, the originating object has no other way of determining how its lifetime relates to that of the internally stored copy of the pointer.

Compiling and Integrating your Model This section outlines the model development lifecycle. The flow-chart in given below illustrates the process.

New pointers synthesized out of "thin air."

Retrieving a copy of an internally stored pointer

An Overview of the Model Development Life Cycle


Figure 4: Model Development Lifecycle


Figure 5: Sample Code

Any changes to the model architecture should be implemented in the assembly (nominally via C# definitions and attributes) this eases model integration and allows for the development of simulations scenarios prior to models being fully implemented. It also enables such complexities as COM interfaces and SMI to be totally hidden from the model developer.

This section provides a simple example of developing a new model, following the model development lifecycle depicted.

This example can be created in a new C# model architecture project or as an extension to the existing Architecture. First we need to define our new model, in this example we will be creating a new payload model.

The first thing we need to do is define our interface. In the example below notice how the NewPayload inherits from IPayload. Any new component defined as inheriting this interface can be plugged into a constellation’s satellite model or in fact any model that expects a child model with the interface IPayload.

Compile the new Architecture and use the GSSF MDE to generate an. xcat. The example below shows the ‘NewPayload’ model together with its properties (displayed in the property grid). Note how the Metadata provided in the Architecture C# file is used by the GSSF Infrastructure to describe the model. You should use these Metadata and descriptions in the Architecture as an aid to the end user of your model.

Example of the Model Development Cycle


Figure 6: Model Properties

The C++ code for the ‘NewPayload’ model can now be generated, the GSSF code generator will create all the necessary header files and wrapper classes so it is only required for you to implement the internals of the model in order to fulfil it’s interfaces. To generate the C++ Code click the right mouse button on the model in the Model Catalogue explorer and select "Generate Code". You will then be presented with the code generation dialogue box.

Figure 7: Model Code Generation Window

As we have not generated any code previously for this model you should set all the generation options and projects to True. You should then click the Generate C++ button, after a few seconds successful generation will be indicated.


By default the GSSF places generated code into the same folder as the Architecture files. This section deals only with the model implementation but note that a CppUnit test fixture has also been generated. Open a Windows Explorer and view the ‘C:\Model’ folder where you placed the Architecture files.

Figure 8: Model Source Files

The NewPayloadTestFixture and the NewPayloadTestRunner are described later in the section on testing. Open the NewPayload.vcproj file in Microsoft Visual Studio .NET you should implement the main part of the new model in the ‘_impl.cpp’ and ‘_impl.h’ files. These are the main working areas while all the code generated by GSSF has been placed in the generated code folder. Changes to your model’s interface or properties should be carried out in the C#, the. xcat and then the model wrapper code regenerated from the MDE. You should be careful not to overwrite the model implementation files by mistake while generating new wrapper code.

The GSSF MDE provides an option to generate a CppUnit testing framework. This framework gives the model developer a head start in producing unit tests for their model. A generated CppUnit test fixture defines a skeleton for the implementation of a test harness. A number of files are automatically generated by the MDE these are:

• CppUnit test fixture header file (modelnameTestFixture.h). This file contains #includes of necessary CppUnit files and the model’s header file. It defines a test fixture class that inherits from the CppUnit test fixture class and is declared as a ‘friend’ of the class under test. This allows the test fixture access to all members of the class under test. The macros CPPUNIT_TEST_SUITE, CPPUNIT_TEST and CPPUNIT_TEST_SUITE_END are used to define the tests to be run as part of the test fixture. Each test method that is to be run as part of the fixture must appear within the CPPUNIT_TEST_SUITE section. The setup and teardown methods are run at the start and end of a fixture respectively. They should be used for any initialisation or cleanup that is required.

Unit Testing


Figure 9: Example of a Generated TestFixture header file

• CppUnit test fixture .cpp file (modelnameTestFixture.cpp). This file contains the implementations of the test methods identified in the test fixture header file. By default the generated file will contain CppUnit assertions for each method of the class under test, this file is the main working area for the modeller to implement the unit test harnesses for their model. The default generated assertions are simply templates and should be replaced by the appropriate test harness code. CppUnit provides a basic set of macros to allow the checking of method return values, fields and properties. There are no real limitations on the use of CppUnit and it remains up to the modeller to devise tests that exercise the unit under test to an appropriate level. Tests should be implemented which exercise the unit to the required level of coverage. An example test harness is shown below (the original generated code remains in the test harness as comments, this is for illustration purposes only).


Figure 10: Example CppUnit test fixture .cpp file

• CppUnit test fixture project file (modelnameTestFixture.vcproj). This file is a visual studio .NET / C++ project file containing the settings necessary to build the CppUnit test fixture.

• CppUnit Test Runner files (modelnameTestRunner.h & .cpp). These files are automatically generated and require no modification by the modeller, they are contained in their own project which should be identified as the ‘Startup Project’ in Visual Studio .NET. When run this test runner will start a console window and output the test results from the execution of the test harness.

It is recommended that after the GSSF code generator has created the test harness projects they should be added to the same Visual Studio solution as the model, this way it is easier to keep the model implementation and test harness up to date and consistent.

Generating a Model Report The Model Report provides information pertaining to models in detail. In GSSF Model Reports can be generated with instructions given as follows.

Select the Model Catalogues tab widget list from left panel of GSSF workspace and expand the node Model Catalogues [Type] Model Catalogues, where type can be SVS (Service Volume Simulation) or RDG (Raw Data Generation).


Figure 11: Select Model Catalogue

The Model Catalogues node contains models in the namespace Space, User, Environment etc. Select any of this namespace and expand it to view models.

Figure 12: Select Models

Select a model and click the right mouse button and select "View Report" in the context menu.


Figure 13: Select Model View Report


Figure 14: Model Report Properties

The Model report is displayed in the centre of the workspace as shown below.


Figure 15: Example Model Report

Overview on Infrastructure API Functions Table 4 provides an overview on all GSSF infrastructure API functions.

Table 4 – GSSF Infrastructure API Functions

API Function Description

static HRESULT Create(std::string interfaceName, void **ptr);

Creates an instance of a model

HRESULT Load(ILoadData *data); Loads the prepared data into the model

HRESULT SwitchInterface(std::string interfaceName, void **ptr);

Switch the model to another interface

HRESULT get_Fields(ITypeInfoCollection** baseTypeFields);

Publish the data of the model for the RTE

void AddRef(); Incresses the reference count of the model instance

ULONG Release(); Decreases the reference count of the d l i


model instancce

int GetModelUniqueId(); Gets the UniqueId of the model

IObject* ConnectToKnownObject(const char* objectName, const char* interfaceName);

Connects the model to a Service

HRESULT LogInformation(string s); Log Information output for the model

HRESULT LogEvent(string s); Log Event output for the model

HRESULT LogWarning(string s); Log Warning output for the model

HRESULT LogError(string s); Log Error output for the model

More Information on GSSF Modelling GSSF was developed in line with the spirit of Simulation Model Portability (SMP) [RD 2]. Currently at the time writing this documentation SMP2 standardisation is being defined by European Space Agency (ESA) and industries. SMP2 is expected to provide the necessary flexibility and elements to fully exploit the envisaged GSSF Modelling capabilities.

Scheduler Models Interaction This section describes shortly the interaction between the Simsat scheduler and the RDG models during the simulation runtime. As example a typical RDG simulation is considered which is used to create a rinex observation file The Figure 16 depicted below shows the interaction between the RDG models and the scheduler involved in this kind of simulation. The child models (e.g. Orbit Propagator, Multipath) are not depicted in the figure because they are not called directly by Simsat but by their parent models (e.g. Satellite, Receiver). An exception is the Environment model, which is a global service model used by the receiver to get the data send by the satellites. The Recorder is a component called directly by Simsat Scheduler in order to write the data provided by the receiver into the Binary File. The execution order is not randomly. Looking at the figure the models are called by the scheduler from top to down. The execution order is very important because there are data dependencies between the models. For example the satellite has to be executed before the receiver because the receiver algorithms need for the execution input data provided by the Satellite and Environment models. The simulation mode (e.g. free running, real time) depends on the type of the Scheduler. For the RDG free running Scheduler is used that means the models are executed as fast as possible.


Figure 16: Scheduler Models interaction

What do you want to simulate today? Using GSSF Chapter 10: Importing and Exporting Data • 137

Chapter 10: Importing and Exporting Data

GSSF - Importing and Exporting Data GSSF has the flexibility to Import and Export files of different type based on the Models that are used in GSSF. In order to have flexibility to Incorporate these features GSSF has in built Exporter Catalogue, where custom made exporters can be incorporated into GSSF.

The following figure provides an overview on which data formats can be imported and exported at what stage of the GSSF workflow.

Figure 1: GSSF Import Export Overview

GSSF Supported Formats The following sections will give an overview of formats of files that are supported by GSSF.

GSSF is fully compatible in writing the following graphic file formats. The types of graphic file that are supported by GSSF are listed below.

JPG, JPEG, BMP, DIB, GIF, WMF, EMF, EXIF, PNG

Image Formats

138 • Chapter 10: Importing and Exporting Data What do you want to simulate today? Using GSSF

GSSF can read the following file formats to set the constellation parameters for the space segment and this is useful to define constellation in efficient manner. The types of constellation files supported are listed below.

YUMA

TLES

XML , CSV

Importing Data from an XML File GSSF uses XML Datasets for saving Simulation results from the pre-recorded binary “xxx.rec” files. This is possible by including the recorded files into the Data Postprocessor of the Analysis. Now in the file menu of the Data Postprocessing window select Save XML Dataset… to save the files into a XML Dataset.

This XML Dataset can be used to analyse and visualise results by opening the XML Dataset from the file menu of Data Postprocessing… window.

The file format of the XML data files is the one of the ADO.NET Dataset.

Importing Data from a Constellation File GSSF has feature to define constellation using the Constellation File Wizard. This can be done by following the steps given below.

Step 1: Start Constellation File Wizard, by selecting the Space Segment node in simulation explorer and clicking the right mouse button and navigating to Insert <Constellation> .A dialogue box is displayed with list of constellation type available. Select Constellation file wizard and click OK button.

Step 2: The user will be provided with basic information dialogue. Click on “Select” to proceed.

Step 3: The user can select the file the constellation file to create the constellation. Also users can use the Files of Type text box to select the type of constellation file imported.

In GSSF, YUMA and TLES files are injected during the initialisation of constellation before starting the Simulation. However IGS SP3, can be injected during run time (applicable for RDG only) to simulate the constellation based on the injected sp3 data. For information on IGS SP3 file format please refer to RD 20.

Via browsing the Simulation explorer, the user can access elements that are contained within the Space segment. Properties are again accessible via the property grid for each element selected in the Simulation explorer.

Reading IGS SP3 Files GSSF supports the feature of reading orbit data from IGS SP3 file. Those data then is used instead of propagating the satellite orbits. The steps given below instruct how to configure GSSF in order to use SP3 file for the satellite orbits when running a simulation.

Precondition: The simulation start and stop time must be set within the time available in the SP3 File.

Step 1: Select the 'Scenario' node, expand the explorer view and navigate to 'Environment sp3Reader '.

Step 2: In the property grid of ‘sp3Reader' set the following properties

Constellation File Formats

Data File Formats


• Set the property FileName to the full path of the SP3 file to be used

• Set the property On to true

Step 3: Go to Scenario Space Segment GPS Constellation GPS Satellite [x] (do it for each individual satellite)

• Set the property OrbitType to ExternSource

• Set the property PRNnumber to the relevant PRN number of the satellite from the SP3 file

Now the selected SP3 file will be used by GSSF during the simulation.

[NOTE: IGS SP3 reader feature is applicable to RDG Simulations only]

Reading RINEX Clock Files GSSF supports the feature of importing RINEX Clock files. The steps given below instruct how to import an RINEX Clock file into GSSF simulation. For information on RINEX file format please refer to RD 18. For further information on this reader, please also refer to RD 1.

Step 1: Select the 'Scenario' node, expand the explorer view and navigate to 'Environment ClockReader'.

Step 2: In the property grid of ‘ClockReader' set the 'Property' category value

• Set the property FileName to the full path of the RINEX Clock file to be used

• Set the property On to true

• Set the property Value to GssfTime.ExternalSourceCloc

Step 3: Go to Scenario User Segment User Clock

• Set the property Value to GssfTime.ExternalSourceClock

Now the selected RINEX Clock file will be used by GSSF during the simulation.

[NOTE: RINEX Clock reader feature is applicable to RDG Simulations only]

Importing IONEX File GSSF supports the feature of importing IONEX data file to simulate the environmental condition. The steps given below instruct how to import an IONEX file into GSSF simulation. For information on IONEX file format please refer to RD 18. For further information on this reader, please also refer to RD 1.

Step 1: Select the 'Scenario' node, expand the explorer view and navigate to 'Environment environment envIonosphericDelay TEC Model '.


Figure 2: Importing IONEX Data

Step 2: In the property grid of 'TEC Model' set the 'Property' category value to read 'GssfEnvironment.ENVIonexReader' from the combo list box and key in the file path, where the IONEX file is located in the 'FileName' category.

Figure 3: IONEX Setup

Now the selected IONEX file will be used by GSSF during the simulation.

[NOTE: IONEX and TROPEX reader features are applicable to RDG Simulations only]


Importing TROPEX File GSSF supports the feature of importing TROPEX data file to simulate the environmental condition. The steps given below instruct how to import an TROPEX file into GSSF simulation. For information on IONEX file format please refer to RD 18. For further information on this reader, please also refer to RD 1.

Step 1: Select the 'Scenario' node, expand the explorer view and navigate to 'Environment environment envTroposphericDelay '.

Figure 4: Importing TROPEX Data

Step 2: In the property grid of 'envTroposphericDelay' set the property category value to read 'GssfEnvironment.ENVTropexFileReaderMain' from the combo list box.


Figure 5: Tropospheric Delay Properties

Step 3: Now again select the 'Scenario' node, expand the explorer view and navigate to 'Environment environment envTroposphericDelay Tropex FileReader '.

Figure 6: TROPEX File Reader

Step 4: In the property grid of 'TropexFileReader' enter the "Header" and "Data" file to be used for Tropex data.


Figure 7: TROPEX Setup

Now the selected TROPEX file will be used by GSSF during the simulation.

[NOTE: IONEX and TROPEX reader features are applicable to RDG Simulations only]

Exporting Data to an ASCII File GSSF supports the feature of exporting simulation output data and analysis to ASCII files, i.e. “Comma Separated Values” (CSV) files, which can be read by Microsoft Excel.

Step 1: Run a simulation and process the simulation output data as described in the tutorial’s sections Tutorial 1: Analysing Global Availability of Integrity or Tutorial 2: Analysing Global Dilution of Precision.

Step 2: Select the Data Storage tab page. Expand data storage explorer Data Storage GSSF Data Storage Executions. The Executions folder holds all data from the latest simulation runs ordered by its data and time.

Step 3: Expand the last entry of the Executions folder and select the recorded simulation output data, i.e. a data set starting with Recording_… .

Step 4: Select Export DataSet from the context menu of the dataset. In the Save As dialogue you can enter a file name and a directory in which to export the data set. Click Save button.


Step 5: Expand the Postprocessings entry of the Executions folder. Expand the last entry, which correspond to the last simulation run, and select a data set according to the analysis data you want to export, e.g. Global or Regional DOP_Grid[1].

Step 6: Repeat Step 4.

Via browsing the corresponding directory of the hard disk, the user can verify that the data sets have been exported and written to hard disk. For each table in the data set a separate CSV file has been generated. The names of the files are combined from the user defined file name plus the table name like GDOP for example.

Exporting RINEX Observation and IGS SP3 The RDG functionality of GSSF is directly associated with exporting RINEX observation files. A dedicated tutorial is provided in Section Tutorial 3: Generating RINEX Data. The following exporters are currently available:

• RINEX 2.10 Observation Exporter

• RINEX 2.20 Observation Exporter

• RINEX 2.00 Clock Exporter

For information on RINEX file format please refer to RD 20.

In addition an exporter to IGS SP3 files is available that in particular allows recording of orbit data:

• IGS SP3 Exporter

For information on IGS SP3 file format please refer to RD 20.

Writing Images GSSF is able to write images generated from visualisations of processed simulation output or analysis results to hard disk. This can be done following the steps given below.

Step 1: Generate an image. Examples how to do that can be found in the tutorial’s section (see section Tutorial 1: Analysing Global Availability of Integrity or Tutorial 2: Analysing Global Dilution of Precision).


Step 3: A Save File dialogue is displayed. Enter a name for the image in the File Name text box.

Step 4: Select format of graphics to be exported: Bitmap (.bmp), Windows Metafile (.wmf) or JPEG (.jpg)

Step 5: Click the Save button.

Via browsing the corresponding directory of the hard disk, the user can verify that the images have been exported and written to hard disk.

What do you want to simulate today? Using GSSF Chapter 11: GSSF Tutorials • 145

Chapter 11: GSSF Tutorials

Please find the files needed for tutorial in GSSF Installation CD-ROM in the folder named "Tutorials". It is strongly advised that the person who install's GSSF, should copy the folder into local machine and change the 'Read-only' attribute, before running simulations.

Tutorial 1: Analysing Global Availability of Integrity This tutorial will guide you through steps to perform a Global or Regional Availability of Integrity Analysis based on Service Volume Simulation with GSSF V2.0 release.

Step 1: Launch GSSF, by double clicking on the GSSF V2.0 Icon on your Desktop.

Step 2: Enter the username “Engineer” and the password “<EmptyField>” and click the Login button.

Step 3: In the File menu bar select File Open Simulation.

Preparation

146 • Chapter 11: GSSF Tutorials What do you want to simulate today? Using GSSF

Step 4: An Open Simulation dialog is displayed. Select the simulation file named "AvailabilityOfIntegrity.gssf" located in the folder named "Tutorial\Tutorial1”. Click the Open button.

Step 5: Locate the AvailabilityOfIntegrity node to your left side of workspace and expand the explorer. In the Simulations explorer you should find Scenario, Analyses, Recorder, Visualisation and Script Engine nodes.

Loading Simulation


Step 6: Select the Analyses node. Click the right mouse button and select Add Analysis in the popup menu.

Step 7: In the Select Analysis dialogue expand the explorer down to Analysis Catalogues GSSF Analyses Integrity and select "Global or Regional Availability of Integrity without failures" then click the 'OK' button.

Selecting Analysis


Step 8: A Select Element dialog is displayed Check the ‘Grid [1]’ element and click the OK button.

Step 9: A Global or Regional Availability of Integrity without failures analysis node appears in simulation explorer.


Step 10: Select the ‘HAL' field in the property grid of the analysis and enter value “25” and select the ‘VAL’ field and enter value “30”.

Step 11: Select the AvailabilityOfIntegrity node in simulation explorer. Click the right mouse button and select Run in the popup menu.

Running Simulation


Step 12: RuntimeController in the centre tab window of workspace becomes active. After the simulation has been initialised, it runs automatically.

Step 13: Select the job AvailabilityOfIntegrity in the Runtime Controller. The status of completion of this process is indicated by progress bar. The simulation will stop at user specified end time. To abort the simulation at any point of time, click on Pause and Abort button in sequence in the Runtime Controller.

Step 14: A map plot will be initialised automatically in the centre of workspace after the recorded data has been processed.

Step 15: In the DataColumn category of the map plot property grid you can select Availability_gic, Availability_raim or Availability_comb depending on the integrity results needed to be displayed.

Visualising Result


Step 16: A map with Integrity results is displayed in the centre of the workspace.


Step 17: The various projections of the plot can be viewed by selecting the options available in the Map Projection drop down combo list box.

Step 18: Select Tools Export Graphic. A Save File dialogue is displayed. Enter the name ”Availability of Integrity” in the File Name text box and click the Save button.

Step 20: In order to implement the same analysis for different simulation times or time steps, select the AvailabilityOfIntegrity node in the simulation explorer on the left side.

Step 21: In the property grid on the right side and you can set the desired Start Time, Stop Time and Time Step in the Simulation category.


Step 22: If you want to keep the modifications, select the AvailabilityOfIntegrity node and click the Save button. If you want to save simulation under new name, select File Save As, which displays a Save As dialogue. Enter a new name and click the OK button.

Step 22: Repeat from Step 13 to run the newly configured simulation.


Tutorial 2: Analysing Global Dilution of Precision This tutorial will guide you through steps to perform a Global or Regional Dilution of Precision Analysis based on Service Volume Simulation with GSSF V2.0 release.


Step 2: Enter the username “Engineer” and the password <emptyfield> and click the Login button.

Step 3: In the File menu bar select File Open Simulation.

Step 4: An Open Simulation dialog is displayed. Select the simulation file named "GlobalDOP.gssf" located in the folder named "Tutorial\Tutorial2”. Click the Open button.

Preparation

Loading Simulation


Step 5: Locate the GlobalDOP node to your left side of workspace and expand the explorer. In the Simulations explorer you should find Scenario, Analyses, Recorder, Visualisation and Script Engine nodes.

Step 6: Select the Analyses node. Click the right mouse button and select Add Analysis in the popup menu.

Selecting Analysis


Step 7: In the Select Analysis dialogue expand the explorer down to Analysis Catalogues GSSF Analyses DOP and select Global or Regional DOP then click the 'OK' button.

Step 8: A Select Element dialog is displayed. Check the ‘Grid [1]’ element and click the OK button.


Step 9: A Global or Regional DOP node appears in the simulation explorer view.

Step 10: Select the GlobalDOP node. Click the right mouse button and select Run in the popup menu.

Step 11: RuntimeController in the centre tab window of workspace becomes active. After the simulation has been initialised, it runs automatically.

Step 12: Select the job GlobalDOP in the RuntimeController.The status of completion of this process is indicated by progress bar. The simulation will stop at user specified end time. To abort the simulation at any point of time, click on Pause and Abort button in sequence in the Runtime Controller.

Running Simulation


Step 13: A map plot will be initialised automatically in the centre of workspace after the recorded data has been processed. In the Data table category of the map plot property grid you can choose from GDOP, TDOP, PDOP, HDOP or VDOP. In this case choose PDOP

Step 14: In the DataColumn category of the map plot property grid you can select Minumum, Maximum, Mean and Percentile 95% for the corresponding DOP value. In this case choose Mean.

Visualising Result


Step 15: A map with DOP results is displayed in the centre of the workspace.

Step 16: The various projections of the plot can be viewed by selecting the options available in the MapProjection drop down combo list box.



Step 18: A Save File dialogue is displayed. Enter the name ”Global DOP” in the File Name text box and click the Save button.

Step 19: In order to implement the same analysis for different simulation times or time steps, select the GlobalDOP node in the simulation explorer on the left side.

Step 20: In the property grid on the right side and you can set the desired Start Time, Stop Time and Time Step in the Simulation category.

Step 21: If you want to keep the modifications, select the GlobalDOP node and click the Save button. If you want to save the simulation under a new name, select File Save As, which displays a Save As dialogue. Enter a new name and click the OK button.

Step 22: Repeat from Step 13.


Tutorial 3: Generating RINEX Data This procedure will guide you through steps to generate RINEX data based on Raw Data Generation Simulation with GSSF V2.0 release. For the RINEX file format, please refer to RD 18.


Step 2: Enter the username “Engineer” and the password <emptyfield> and click the Login button.

Step 3: In the menu bar select File Open Simulation.

Step 4: A File Open dialog is displayed. Select the simulation file named "Rinex.gssf" located in the folder named "Tutorial\Tutorial3”. Click the Open button.

Preparation

Loading Simulation


Step 5: Locate the Simulation node Rinex to your left side of workspace and expand the explorer. In the Simulation explorer you should find Scenario, Analyses, Recorder, Visualisation, ScriptEngine and Exporters nodes

Step 6: Select the Exporters node. Click the right mouse button and select Add Exporter in the popup menu.

Selecting Exporter


Step 7: In the Select Exporter dialogue expand the explorer down to Exporter Catalogues GSSF Exporter and select RINEX 2.10 Observation Exporter then click the 'OK' button.

Step 8: A Select Element dialog is displayed. Check the ‘GSS [1]’ element and click the OK button.


Step 9: An exporter node "RINEX 2.10 Observation Exporter" appears in the simulation tree.

Step 10: Select the Rinex node. Click the right mouse button and select Run in the popup menu.

Running Simulation


Step 11: Runtime Controller in the centre tab window of workspace becomes active. After the simulation has been initialised, it runs automatically.

Step 12: Select the job Rinex in the Runtime Controller. The status of completion of this process is indicated by progress bar. The simulation will stop at user specified end time. To abort the simulation at any point of time, click on Pause and Abort button in sequence in the Runtime Controller.

Step 13: Rinex Exporter will be initialised automatically to process the recorded data and in the centre of workspace Rinex Observation file is displayed.


Tutorial 4: Modify Algorithm using GSSF NOTE: This section deals with modifying and compiling source code and requires basic software development knowledge.

Step 1: Locate the folder ‘Source‘ on the GSSF V2.0 delivery CD-ROM

Step 2: Copy the content to a place on your hard disk called <GSSF_V2_Source>

Step 3: Launch Microsoft Visual Studio 7.0

Step 4: Open the Visual Studio solution file ‘Architecture.sln’ from the path <GSSF_V2_Source>\ModelDevelopmentEnvironment\Models\Svs\Specification’ via File Open Project menu item

Step 5: Locate ‘GicOnlySvs.cs’ file in the Solution Explorer window and open it.

Step 6: Navigate to the fields section inside the opened C# source code file.

Step 7: Introduce the new parameter (property) to the model/algorithm

Example:

[Range(0, 10000)]

[Def(20.0)]

[Unit(Units.m)]

[Vis(GssfAttributes.Visibility.ReadWrite,Category.Advanced)]

double AlarmLimit;

• Specify the new parameter as a C# field

• Use a basic C# type for the parameter, e.g. ‘double’, ‘int’ or ‘bool’

• Specify the meta-data for the new parameter by using C# attributes (see example above)

Step 8: Select project node ‘Architecture’ in the Solution Explorer

Step 9: Select ‘Project Properties’ menu item

Step 10: Set property XML Documentation File under ‘Configuration Properties Build’ to ‘Architecture.xml’

Step 11: Build the solution by selecting ‘Build Build Solution’

Step 12: In case of a successful build close Visual Studio application and go on, otherwise fix the problem and go back to Step 11.

Step 13: Loading a model specification DLL into GSSF

Step 14: Launch GSSF V2 from your Desktop

Step 15: Login as user ‘Modeller’ using an empty password field

Step 16: Close existing model catalogue by selecting File Close from the GSSF main menu

Step 17: Select File Open ModelCatalogue menu item from the GSSF main menu

Step 18: Change ‘Files of type’ drop-down box to ‘All Files (*. *)’

Step 19: Open model catalogue DLL file ‘Architecture.dll’ from ‘<GSSF_V2_Source>\ModelDevelopmentEnvironment\Models\Svs\Specification\bin\Debug\’

Preparation

Changing Model Specification


• The model information contained in the model catalogue DLL will be converted to XML file format and read into the GSSF model catalogues explorer.

Step 20: Locate model ‘GicOnlySvs’ in the model catalogue explorer under ‘User’ category

Step 21: Right click mouse on the model node and select ‘Generate Code’

Step 22: A window will be shown with the title Generate User.GicOnly Svs.

Step 23: Press 'Generate C++' button on the Generate Code window.

Step 24: After a successful code generation a message box with the content User.GicOnlySvs is generated will be shown.

Step 25: Press the OK buttons on the two windows in order to close them

Step 26: Navigate to the folder in the path mentioned as follows ‘<GSSF_V2_Source>\ModelDevelopmentEnvironment\Models\Svs\Specification\bin\Debug\User.GicOnlySvs\GicOnlySvs\Generated Code’ using the Windows Explorer

Step 27: Copy the files ‘User.GicOnlySvs.cpp’, ‘User.GicOnlySvs.h’, ‘User.GicOnlySvsReflection.cpp’ to the folder in the path mentioned below‘<GSSF_V2_Source>\ModelDevelopmentEnvironment\Models\Svs\User\GicOnlySvs>‘

Step 28: Navigate to the folder in the path mentioned as follows ‘<GSSF_V2_Source>\ModelDevelopmentEnvironment\Models\Svs\User\GicOnlySvs>‘

Step 29: Delete the files ‘GicOnlySvs.cpp’, ‘GicOnlySvs.h’, ‘GicOnlySvsReflection.cpp’

Step 30: Rename the file ‘User.GicOnlySvs.cpp’ to ‘GicOnlySvs.cpp’

Step 31: Rename the file ‘User.GicOnlySvs.h’ to ‘GicOnlySvs.h’

Step 32: Rename the file ‘User.GicOnlySvsReflection.cpp’ to ‘GicOnlySvsReflection.cpp’

Step 33: Open the Visual C++ project file ‘GicOnlySvs.vcproj’ with Visual Studio 7.0

• The solution auto-load feature of Visual Studio will load the solution that contains the GicOnlySvs project file automatically. Unfortunatelly this solution file references two other project files (GicRaim, RaimOnly) that can’t be loaded with this solution and are not necessary anyway. Please ignore the error message and remove the two not needed project files from the solution.

Step 34: Locate ‘GicOnlySvsReflection.cpp’ file in the Solution Explorer window and open it

Step 35: Change the include statement #include "User.GicOnlySvs.h" to #include "GicOnlySvs.h"

Step 36: Locate ‘GicOnlySvs.cpp’ file in the Solution Explorer window and open it

Step 37: Change the include statement #include "User.GicOnlySvs.h" to #include "GicOnlySvs.h"

In order to modify the model implementation and use the new introduced parameter…

• Locate ‘GicOnlySvs_impl.cpp’ file in the Solution Explorer window and open it

Generating Model Wrapper Source Code

Modifying Model Source Code


• Browse to method ‘GicOnlySvs_impl::RxPosIntegrity(…)’ and do the necessary changes using the new parameter ‘this->AlarmLimit’

Step 38: Build the solution by selecting Build Build Solution

Step 39: In case of a successful build close solution and go on, otherwise fix the problem and go back to Step 38

Step 40: Open the Visual C++ project file ‘SvsMain.vcproj’ from folder ‘<GSSF_V2_Source>\ModelDevelopmentEnvironment\Models\Svs\Main\>‘

Step 41: Rebuild the solution by selecting Build Rebuild Solution

• The resulting DLL (SvsMain.dll) will be registered to the system automatically and contains the new, modified model library that will be used in future simulations.

Step 42: Going back to the running GSSF application, save the new model catalogue by selecting File Save Architecture.dll As to the installation folder of GSSF (default: ‘C:\Program Files\VEGA IT GmbH\GSSF V2.0 RC 2’) under the new file name ‘SvsModelCatalogue.xmdl’ (File type: GSSF Model Catalogue Files (*.xmdl))

• You will be asked to replace the existing model catalogue file. Please answer ‘Yes’ here.

Step 43: Close GSSF application

In order to use the new modified model in a simulation, please refer to the User Manual of GSSF on how to create a scenario and simulate it.

In future versions of GSSF the steps 26 – 29 and 31 – 34 don’t need to be executed. Those source code corrections became necessary because of the model source improvements and re-structuring that were performed as result of the GSSF CDR meeting. We need to implement the adaptation to the new structure in the GSSF code generation feature.

Building Model Library

Saving New Model Catalogue

170 • Chapter 12: System Administration What do you want to simulate today? Using GSSF

Chapter 12: System Administration

Please note that all the below administration tasks can only be done by a machine user with administrator priviledges.

Installing GSSF The User can install GSSF by double clicking on the setup file setup.exe.

Figure 1: Installer Window

This will automatically launch the Installation Wizard below. Press “Next” to proceed. A window is displayed were the user can change the destination directory or leave it as it is. The default directory is “C:\Program Files\VEGA IT GmbH\GSSF V2.0". Please click “Next” to proceed with the installation.

During installation the setup will provide status information and a installation progress bar as illustrated below. It would take few minutes to complete the installation process.

What do you want to simulate today? Using GSSF Chapter 12: System Administration • 171

Figure 2: Installation Progress Window

The user is informed upon completion of the installation by the window below. Confirm by pressing the Finish button to close this dialogue.

Figure 3: Installation Complete Message

GSSF is now installed on your machine. Double clicking the icon on the desktop as shown below will launch GSSF.


Figure 4: Desktop Icon

Note:

• In order to run GSSF the user must have third party software installed as defined in Section Hardware and Software Configuration. The current installation wizard will also install the .NET Framework 1.1 on you machine.

• After installing GSSF, all the content of 'Tutorial' folder in GSSF Installation CD must be copied to local drive and the read only attribute must be removed. This process enables system users, with limited privileges to access these files.

Un-Installing GSSF The User can Un-install GSSF by navigating to the control panel of Windows OS.In the Start menu open the Control Panel.

Figure 5: Control Panel

Select "Add or Remove Programs" item and double click your left mouse button. Add or Remove Programs window is displayed. Select "Galileo System Simulation Facility" and click the "Change/Remove" button.


Figure 6: Add or Remove Program Window

An installshield wizard window is displayed with information on Un-installation options. Please select "Remove" radio button from the installshield window and click Next button to proceed with the Un-installation to the GSSF.

Figure 7: Select Un-installation Option

A 'Confirm Uninstall' dialogue will prompt user to confirm the Un-installtion process. During Un-installation, the wizard will provide status information and a Un-installation progress bar as illustrated below. It would take few minutes to complete the Un-installation process.


Figure 8: Un-installation Progress Window

The user is informed upon completion of the Un-installation by the window below. Confirm by pressing the Finish button to close this dialogue.

Figure 9: Un-installation Complete Message

GSSF is now installed on your machine. Double clicking the icon on the desktop as shown below will launch GSSF.

Setting Up User Accounts and Privileges GSSF Administrative User can add User accounts and assign privileges by selecting the User Communities tab from the left side window. (Note: Only Administrator can access this User Communities list and create user account, assign privileges)


Please note that the GSSF administrator also needs to be the administrator of the machine where GSSF was installed. Administrator priviledges (on machine level) are required in order to be able to save modified user community files.

Administrator must select 'GSSF User Community', and click the right mouse button and navigate through Add Profile.

Figure 10: User Communities

This process will create a new Profile and the Administrator can assign name and privileges for the profile. Select the created profile node click the right mouse button and select "Edit" in the context menu.

Figure 11: Edit User Profile


A window is displayed in the centre of the workspace where the privileges for the profile created can be set by select the respective menu items that profile can access.

Figure 12: User Profile Overview

An administrator who is modifying a users profile or creating a new one should never deselect (disable) the menu item File->Exit, since this would remove the possibility to exit the application from the File menu.

After assigning the privileges the profile is saved by selecting the "Save Profile GUI Configuration" in the right click context menu of the newly created profile.


Figure 13: Save User Profile GUI Configuration

Similarly user accounts to access GSSF can be created and the Account can be assigned a profile pre-defined by the administrator. Select GSSF User Community, and click the right mouse button and navigate through Add Account.

Figure 14: Insert User Account

Now the name and profile for the newly created account can be assinged by selecting the created account node in GSSF User Community explorer and changing the name in the "Name" row of property grid.


Figure 15: Assign Name to User

Select the "Profile" row in the property grid, a combo list will display the profiles available and the adminsitrator can select the profile to be assigned for the newly created account.

Figure 16: Assign Profile to User

In case if the Administrator wants to change the password for any user account select "Change Password" from the context menu of the account.

Figure 17: Change Password for User Account

A Change Password dialogue is displayed .The Administrator must type the old password and must type the new password to be replaced and confirm the same. Click the OK button.


Figure 18: Change Password Dialogue

Default User Accounts By default, a set of predefined user accounts is available that matches the corresponding user profiles. In case of "Guest" and "Administrator", the default user name and the applicable user profile name match as in typical windows applications.

Default User Account Applicable User Profile Default Password

Modeller Model Developer (no password)

Navigator Navigation Expert (no password)

Engineer System Engineer (no password)

Administrator Administrator admin

Guest Guest guest

The user may log in as any of the above. Restrictions of the corresponding user profile will apply.

180 • Chapter 14: Troubleshooting What do you want to simulate today? Using GSSF

Chapter 14: Troubleshooting

How to Handle Common Problems While using GSSF, a user might experience common problems that can be divided into several categories. This section provides an overview on these categories as well as how a user should proceed in order to resolve the problem.

Should a user have difficulties installing GSSF, it is recommended to refer first to the relevant section in the present documentation. In addition, the release documentation provided with GSSF will identify steps to follow during installation.

As a second step it is recommended to contact your local system administrator in order to exclude that any local hardware and or operation system limitations impact installation.

In case the problem could still not be resolved, please contact the GSSF helpdesk at [email protected].

Should the user experience problems during runtime of GSSF, it is recommended to consult the sections of the present documentation related to the task the user intends to carry out. In case no discrepancy can be identified between the task as performed by the user and as described in the user manual, please contact the GSSF helpdesk at [email protected].

Should the user experience runtime performance problems, the task manager of Windows should be checked for unexpected tasks running in the background. Further, it is recommended to identify whether the hardware satisfies the minimum hardware specification identified in this operations manual. For extensive simulations, in particular related to Raw Data Generation, the recommended hardware configuration applies as identified in this operations manual. Please also consult your local administrator for any local hardware or operations system setting that limit the runtime performance. In case, none of the above applies to the observed runtime performance problem, please contact the GSSF helpdesk at [email protected].

GSSF Beta versions are not kept upward compatible. Therefore, any simulation and/or scenario defined and saved with a previous Beta version of GSSF cannot be loaded and reused with later Beta versions. Starting form GSSF V2.0, upward compatibility is however maintained. In case a simulation and/or scenario file prepared with a compatible version of GSSF cannot be loaded, please contact the GSSF helpdesk at [email protected] for support.

Messaging GSSF is designed to support the user by means of context sensitive limitations, preventing faulty settings. Therefore, no specific error messaging is required as with common Windows applications. Should the system throw an exception, this is not considered proper operation or messaging in support of the user. In such a case, the user is experiencing a

During Installation

At Runtime

Compatibility

What do you want to simulate today? Using GSSF Chapter 14: Troubleshooting • 181

software problem that should be reported immediately as defined in the following section.

Software Problem Reporting Software Problems should be reported using a dedicated form, clearly specifying the experienced problem. This form should be submitted via email to [email protected] identifying the originator and date when the problem occurred. It is mandatory to identify, which version of GSSF was used. Furthermore, it is very helpful to add the scenario definition if available.

Upon reception, the GSSF helpdesk will forward the problem report to the GSSF team, where the problem is confirmed, the severity of the problem is identified and proper actions are taken. All software problems are tracked in a dedicated database at VEGA and the originator will be informed on the status of the problem resolution.

Software Problem Report

PRobLem Description

GSSF VERSION USED

Hardware and Operation System

ORIGINATOR (CONTACT DETAILS)

DATE:


APPENDIX A SVS REFERENCE SCENARIO This appendix contains the GSSF V2.0 SVS Reference Scenario.

(External to this document).

What do you want to simulate today? Using GSSF Chapter 14: Troubleshooting • 183

APPENDIX B RDG REFERENCE SCENARIO This appendix contains the GSSF V2.0 RDG Reference Scenario.

(External to this document).


APPENDIX C BINARY FILE FORMAT

This appendix contains the GSSF V2.0 Recorded Binary Data Format. (External to this document).

What do you want to simulate today? Using GSSF Index • 185

Index

A About GSSF 1 An Introduction to GSSF Code

Generation 117 An Overview of the Model

Development Life Cycle 125

Analyses that are Applicable to GSSF RDG 9

Analyses that are Applicable to GSSF SVS 6

AND Alpha-Numeric Display Applicable Documents 4 Apply Mathematical function to

Processed Data 84 At Runtime 180 Attributes 118

B Background Information 3 Building Model Library 169

C Changing Model Specification

167 Changing Parameter Values at

Run-Time 40 Chapter 1

Overview 1 Chapter 10

Importing and Exporting Data 137

Chapter 11 GSSF Tutorials 145

Chapter 12 System Administration 170

Chapter 14 Troubleshooting 180

Chapter 2 GSSF at a Glance 5

Chapter 3

Getting Started 13 Chapter 4

Simulating 29 Chapter 5

Configure Timeline 46 Chapter 6

Configure Scenario 53 Chapter 7

Analysing Data 77 Chapter 8

Visualising Data 93 Chapter 9

Modelling in GSSF 117 Comparing Data 88 Compatibility 180 Compiling and Integrating your

Model 125 Conceptual Summary and

Objectives 5 Configure UERE for User

Receiver 67 Constellation File Formats 138 Constellation File Wizard. 60 Contact Us 3 Creating a New Scenario 53 Creating a New Simulation 29 Creating and Modifying Model

definitions 122

D Data File Formats 138 Default User Accounts 179 Define Analysis Control

Parameters 81 Defining a New Space Segment

56 Defining a New User Segment 64 Defining Analysis Parameters 80 Defining Output-Data

Visualisations 83 During Installation 180

E Editing a Scenario 54 Editing Projects

The Edit Menu 22 Editing Simulation 30 Empty Constellation 61 Example of the Model

Development Cycle 127 Executing Analysis 83 Executing Projects

Runtime Menu 23 Exporting Data to an ASCII File

143 Exporting RINEX Observation

and IGS SP3 144 External ICDs 4

186 • Index What do you want to simulate today? Using GSSF

Extracting Grid Data 90

F Fetching a global variable 124 File Structure in GSSF 20 Flexibility 11

G Galileo System Simulation

Facility 5 General Guidelines 121 Generated Code 122 Generating a Model Report 131 Generating a Scenario Report 75 Generating a Simulation Report

42 Generating Model Wrapper

Source Code 168 Getting Help 28 Global Navigation Satellite

System Galileo 5 GRD Graphic Display GSSF - Importing and Exporting

Data 137 GSSF and Modelling 117 GSSF Supported Formats 137

H Hardware and Software

Configuration 1 How to Handle Common

Problems 180

I IDE Integrated Development

Environment Image Formats 137 Implementing a Model 123 Importing Data from a

Constellation File 138 Importing Data from an XML

File 138 Importing IONEX File 139 Importing TROPEX File 141 In-out parameters to functions

124 Installing GSSF 170 Interfacing Capabilities 11

L Loading Simulation 146, 154,

161 Logging and Message

Monitoring 27 Login and Start Page 14

M Managing Projects

The File Menu 21 Messaging 180 Model Definition 117 Model Development Guidelines

121 Model Internal ICDs 4 Modelling Capabilities 9 Modelling Capabilities in GSSF

117 Modifying Model Source Code

168 More Information on GSSF

Modelling 135

N New pointers synthesized out of

125

O Overview on Infrastructure API

Functions 134

P Pausing and Resuming a

Simulation 36 Preparation 145, 154, 161, 167

R RAMS Support in GSSF 92 Reading IGS SP3 Files 138 Reading RINEX Clock Files 139 Reference Counting 123 Reference Documents 3 Reporting Problems 3 Retrieving a copy of an internally

stored pointer 125 Running Simulation 149, 157,

164

S Saving New Model Catalogue

169 Saving Visualisations 113 Scheduler Models Interaction

135 Scheduling Simulation - Batch

Mode 36 Scope of Document 1 Search Window 26 Selecting Elements - Analysis 80 Selecting Analysis 147, 155 Selecting Exporter 162

What do you want to simulate today? Using GSSF Index • 187

Selecting Models and Algorithms 55

Selecting/Editing Analyses 77 Set Simulation Time and

TimeStep 33 Setting Up User Accounts and

Privileges 174 Simulation and Analysis

Capabilities 6 Simulation Type 29 Software Problem Reporting 181 Specifiying Script Execution 51 Specifying Data to Record 30 Specifying Failures 49 Specifying Feared Events 48 Starting a Simulation 35 Starting GSSF 13 System Internal ICDs 3

T Terminating a Simulation Early

36 The GSSF Workspace 14 The Model Architecture 121 Tutorial 1

Analysing Global Availability of Integrity 145

Tutorial 2 Analysing Global Dilution of

Precision 154 Tutorial 3

Generating RINEX Data 161 Tutorial 4

Modify Algorithm using GSSF 167

Typographical Convention 1

U Un-Installing GSSF 172 Unit Testing 129

V Visualisation of Recorded Data

31 Visualising Data on Map Plots 98 Visualising Data on Pair Plots

107 Visualising Data on Radar Plots

104 Visualising Data on Stanford

Plots 110 Visualising Data on Time Plots

93 Visualising Result 150, 158 Visualising Saved Data 114

W Walker Wizard 57 Writing Images 144

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