Jamison ~uhn*

Northrop Corporation Aircraft Division

Hawthorne, california

ABSTRACT

This paper will present the techni- cal approach that the Northrop Corpora- tion Aircraft Division's Integrated Sys- tems Simulation Laboratory has taken to provide the projects at Northrop with an advanced manned interactive multiple- engagement tactical air combat mission simulation. The hardware and software configuration to enable real-time evaluation will be described. In addi- tion, this paper will present repre- sentative formats depicting the nature of the data obtained in this facility. There will be a discussion of the expan- sion that is now in progress to enhance the laboratory's capabilities and in- crease the computational capacity.

INTRODUCTION

In the early 1980s Northrop's In- tegrated Systems Simulation Laboratory (ISSL) conducted a proof-of-concept test by linking its two domed simulators and performing the first one-on-one air com- bat engagement simulation. The potential for expanding this capability was fueled by the activities of other companies in the field. McDonnell Douglas Corporation had completed their AMRAAM Operational Utility Evaluation (OUE) at about that time. The ability to display information relating to multiple aircraft demon- strated by Cubic Corporation on the ACMI ranges provided the ideas for Northrop to expand and to include many of these features using the latest technology. Over the years, models have been developed from the various R&D projects using the laboratory. A capability has evolved to model the aircraft as an in- tegrated system. This integrated simula- tion includes the avionics systems, weapons, IR and RF signature patterns, control systems, air vehicle perfor- mance, and the environment. Combining these systems in a single simulation permits the fine-tuning of the tactical aircraft and the development of its as- sociated weapon systems. Today, any variety of up to nine of these simulated aircraft can be combined using any mix of two domed simulators and seven manned

* Senior Engineer, Member AIAA Copyright Q 1988 by Northrop Carp. Published b the American Institute Of Aeronautics and Astronautics, Inc. with permission.

interactive control stations. This multiple-engagement simulation capabil- ity now provides users of the facility an environment for the development and evaluation of such diverse techologies as

o avionics software in the mission environment;

o pilot/vehicle interface studies ;

o sensor blending/fusion algo- rithms and fire/ weapon con- trol algorithms;

o performance designs and measurements in simulated flying/ tactical situations;

o electronic countermeasure systems;

o multiple-engagement/inter- netted tactics;

o air-to-air, surface-to-air missile delivery and avoid- ance; and

o situational awareness.

It is here that design and technol- ogy tradeoffs can be conducted in real- time to evaluate/validate aircraft and system designs. Numerous trials can be run, data gathered, concepts examined and modified, initial conditions changed, and the design evaluated again. All this can be done in the course of a day's trials. Northropls ISSL facility incorporates a flexible modular design in both hardware and software farmats. This modular capability allows for dif- ferent aircraft designs to be examined with minimal impact on down-time or turn-around time, thus sharing assets and schedules among a multitude of projects using the laboratory. When hardware-in-the-loop is anticipated in a simulation, the software is modularized to represent the hardware and its inter- faces. The system can be quickly recon- figured to provide any combination of Red and Blue forces, including various sensor, weapon, and airframe mixes. Menu-driven software, controlled by simulation executives, allows the test engineer to build flight simulation modules based on the mission scenario supplied by the test director.

FACILITY CONFIGURATION

The ISSL facility shown in Figure 1 is comprised of two fixed-based visual dome simulators (Domes 1 and 3), a moving-based visual simulator (Dome 2), seven manned interactive control sta- tions, a Battle Situation Room with a Test Director's Station, and three test engineer stations. The motion-based simulator is not part of the overall multiple-engagement ,simulation, but is used for stand-alone flying qualities evaluations. Each domed simulator has its own Test Engineer's Station (TES), but the Dome 3 TES controls the multiple-engagement simulations among all the individual flying elements.

Dome 1

Dome 1 is a 24 foot diameter simulator and, when used stand-alone, is primarily for high-detail air-to-ground flight simulations. A General Electric Compuscene IV color graphics generator driven by a Gould Concept 32/9780 provides the high-detail ground scene and target generation. The total field- of-view is 135 degrees by 45 degrees. Pilot head-slaving of this image in two axes is to be incorporated in the near future. For now, an earth/sky projector provides additional visual cues beyond the 135 degrees displayed by the Compus- cene IV. This six channel system dedi- cates three channels for terrain gener- ation and background targets, one chan- nel for projected targets, and the remaining two channels can be used for sensor displays in the cockpit.

Dome 3

Dome 3 is a 28 foot diameter air combat simulator with two three channel General ~lectric Compuscene I11 systems

that provide a 360 degree-field-of-view color background scene and three high- detail projected targets. Six additional targets can be inserted within the back- ground scene. This dome visual system provides the pilot with a realistic out- the-window aerial combat environment. The Compuscene I11 system is driven by two Gould 32/9750s.

Cock~it Assemblies

The two fixed-based simulators house removable and interchangeable cockpit/crew stations. The cockpit crew station assemblies (situated in the cen- ter of each dome) are representations of modern fighter aircraft. The basic func- tionally equivalent hardware consists of head-down displays, a head-up display, a stick for pitch and roll control, rudder pedals, and a throttle lever. Some crew stations may contain additional hardware, depending on the technology being investigated. These cockpit as- semblies can be changed-out in one work- ing day when projects require their own cockpit configuration.

Manned Interactive Control Stations (MICS)

The MICS, developed by the ISSL, provide high fidelity avionics and weapon systems capabilities with the flexibility to modify or vary parameters during test. Each MICS functions as a separate flight element in the multiple- engagement simulation as shown in Figure 2. The MICS employ a color raster graphic monitor display which combines all the necessary symbology a pilot requires to fly the simulated mission. The MICS also includes a joystick to provide aircraft flight control, weapon firing and avionics mode select, and a thrust control lever (throttle) for

Figure 1. Integrated Systems Simulation Laboratory

136

Figure 2. Typical MICS

simulated engine control. A touchscreen controller provides additional avionics and weapon systems control at the sta- tion.

Battle Situation Room (BSR) and Test Director's Station (TDS)

The BSR is the primary area for monitoring the progress of the air com- bat simulations. The TDS (Figure 3) is located in the BSR. From this vantage point, the test director controls the test using a touch sensitive simulation control display that pages through dif- ferent menus. Features on one page allow the test director to kill off aircraft if they venture into unauthorized flight

Figure 3. Test Director's Station

regions or if they are to be removed from the engagement due to low fuel. Another page of this display permits lldead'l players to be regenerated at selected points in the battle area.

The test director also monitors the engagement using a wGod's-Eye-Vieww dis- play, a parametric display, and an array of color repeater monitors for each MICS and the various domed simulator cockpit displays. The IqGod1 s-Eye-Viewv1 display in Figure 4 presents the test director with the relative position and orienta- tion of all aircraft, the trajectories of in-flight missiles, plus ground-fixed sites such as the FEBA (Forward Edge of the Battle Area), CAP (Combat Air Patrol) points and waypoints. This dis-

Figure 4. "God's-Eye-Vieww

play can be made to center on any com- bination of simulation participants as well as be scaled to the desired spatial area. Horizontal, vertical, and perspec- tive views can also be selected during the engagement.

The parametric display shows rela- tive information between aircraft such as range, differential altitude, who launched a missile at whom for a kill, radar or IR lockons amongst the aircraft, etc. A computer-controlled in- tercom network provides secure com- munication between the team par- ticipants. The test director can talk to the Red and Blue teams separately or at the same time for debriefing the test results. Video taping of any display is possible with manual selection by the test director or through computer con- trolled video switching software.

Other features of the BSR include two large viewing screens, shown on Figure 5. These monitors can be switched between the wGod's-Eye-Vieww, para-

Figure 5. Battle Situation Room

metric, and MICS displays. Additional VHS, BETA, or UMATIC video players allow for pilot or guest debriefing even while another group of pilots may be flying the next trial. A computer terminal is also available for reviewing ''quick- look'' data. This data is a subset of the complete data reduction stored for a particular trial, and it briefly sum- marizes the weapons employed as a func- tion of target and attacker, weapon type, and outcome. Failure codes are provided in the event a weapon fails to kill its target.

Test Enqineer's Station ITDS)

The Dome 3 TES functions as the overall controller and monitor of all the multiple-engagement simulations in the ISSL and the single engagements per- formed in Dome 3. Some of the functions performed at the TES are the assignment of participants to a particular MICS or simulator; specification of software load modules needed to satisfy the requested simulation test; test in- itialization, monitor, and control of the simulation and the equipment in- volved.

Strip chart recorders, magnetic tapes, disk devices, and high-speed printer/plotters monitor the simulation and collect data in real-time to perform post-flight data reduction and analysis. Monitoring of the Red and Blue conversa- tions and pilot comments, as well as secure communication with the test director, is available with the computer-controlled intercom system.

The same color displays presented at the TDS are also available at the TES. In addition, over-the-shoulder cameras are used to display in-cockpit activity on video monitors mounted in the TES control panel. During develop-

ment periods the control of the "God's- Eye-Vieww can be switched to the TES. The parametric display presented at the TDS is repeated here for the Test En- gineer to monitor during the engagement or to act as a debugging device during development periods. The TES simulation c o n t r o l d i s p l a y h a s t h e s a m e capabilities as those at the TDS in ad- dition to initialization displays and simulation control flags. Many of these same capabilities exist at the test en- gineer stations for Domes 1 and 2.

SOFTWARE CONFIGURATION

The majority of software used in the ISSL multiple-engagement simulation was developed by the laboratory to meet project requirements as well as from non-real-time models that allow man-in- the-loop simulation results to be com- pared with known standards. A small per- centage of software has been acquired from outside vendors. The ISSL places much emphasis on the structuring of its software. Every effort is made to develop the software so that it is easy to modify, and thus accept future expan- sions. Parameterization of variables (having most routines data driven) enables a vast amount of software developed by the lab to be made avail- able for multiple projects. This is especially true of routines that would normally be classified. Therefore, a project needs only to modify the data to accommodate their requirements. The major software components can be divided into simulation modeling, simulation in- itialization and monitor, and simulation real-time execution.

Simulation Modelinq

The software modeled, summarized in Figure 6, falls into three categories - avionics, airframe, and simulation en- vironment. Avionics models developed in the ISSL simulate modern and futuristic sensors and displays representative of Blue and Red capabilities. These models include electronically scanned array and gimballed multi-mode radars, IR/EO sen- sors, and a radar warning receiver, all of which can be manipulated with a touchscreen interface by the pilots. The same software models are used for both the MICS and the domes, while separate routines handle the different hardware interfaces. For example, each MICS pilot, functioning as a separate flight element, interfaces with the avionics through a touchscreen attached to a raster color monitor. A joystick con- troller provides aircraft flight con- trol, weapon firing and avionics mode select while a thrust control lever (throttle) simulates propulsion.

The simple out-the-window display on the CRT screen (Figure 7) provides

SIMULATION LOAD MODULES

I b

SIMULATION SOFTWARE MODELING

AVIONICS FUNCTION

Airborne Sensors Gimbaled or ESA Mult~mode Radar

IRiEO Search and Track

Datalink JTIDS

Visual Acquislt~on and Tracking System (VATS)

Electronic Warfare Systems

RWR, M~ss~ le , and Radar Warning

Expendables, Deceptton, Jarnrnmg

Weapons Delivery

Weapon Control and F~ring

Cockpit Weapons D~splay Support

Graphics Display Format

MICS Touchscreen Interface with Color Raster CRT

Cockp~t HOSAT Control w ~ t h Vector andlor Color Raster D~splays

AIR VEHICLE FUNCTION

Aerodynamic Buildup Data Dr~ven Aero Models

Pitch Roll Yaw St~ck Inputs

Simplified Equations of Motion

Forces and Moments

Propulsion

Fuel Flow Tables

Thrust Tables

Aircraft Detection

Radar Cross Sect~on Table Lookup

IR Signature Modeling

ENVIRONMENTAL FUNCTION!

Threats Funct~ons Mlss~le Launch Envelope and Flyout

Bullet Trajectory

Electronic Order Of Battle

CommandlControllCommunicat~on for Weapon Allocation and Conlrol

Early Warning (EW)IGCI S~tes

SAM Sites

Fire Control Radar

Simulated SUIAWACS

Computer Controlled Par t~c~pants

Aggressive Red Fighters

Blue StrikerlBomber

Secure Cornmun~cat~ons

Separate Team Conversations

Dead Players Removed

Separate Lines for Test D~rector and Test Eng~neer

Relat~ve Geometry Target Regenerat~on

--

Figure 6. Simulation Software Modeling

the MICS pilot with basic flight at- titude and altitude information, plus ground cues using a ground grid and an earth-sky pictorial. Visual acquisition software is used at the MICS to simulate a pilot scanning visible portions of the sky with multiple glimpses to detect other aircraft. Using logic based on range, aspect, and visual signature of the aircraft, symbology is provided on the out-the-window display. This symbol- ogy, taking into account cockpit masking angles, cues the pilot to look in the direction where targets would normally be seen if not for display field-of-view limits. Visual identification is en- hanced'with different stick figures to distinguish Red and Blue fighters. This same logic is used to assign aircraft to the target projectors in Domes 1 and 3. Multiple-engagement and internetted tac- tics are available with data linking and simulated JTIDS modeling. Effects of low observability are evaluated by inserting different radar and IR signature pat- terns or employing gaining techniques.

Pilots flying the domed simulators are presented these same avionics fea- tures on the head-up and head-down dis- plays. The sensors are manipulated with

hands-on-stick-and-throttle (HOSAT) con- trols. Touchscreen displays are also being incorporated into new cockpits. The background scene projected on the dome provides the pilot with spatial cuing, as well as targets within range. With the ability to project targets on the inner dome surfaces, one-on-one visual air combat engagements can be conducted between the two domed simulators.

Air vehicle performance is simu- lated using a format that permits dif- ferent aircraft types to be modeled. This feature allows design tradeoffs or mixtures of flight elements to duplicate real-world threats encountered in a multiple-engagement fight. Using simplified equations of motion, the per- formance characteristics of the various aircraft types can be modeled from data tables. These tables include elements such as maximum roll rate (Q), lift, and drag as a function of mach. Additional thrust and fuel flow tables based on power setting, mach, and altitude com- bine with the above data to compute the rotational velocities P, Q, and R. Time lags and gravitational and velocity limits add to the fidelity of the model.

Figure 7. Sample MICS Display

Radar cross sectional area patterns are modeled in terms of azimuth and elevation breakpoints, and multiplica- tive gain factors. The IR signature pattern consists of six components: airframe, inlet, deck, turbine, nozzle, and plume. Each component has a radiance value (as a function of target altitude and mach) and an area value based on relative geometry (azimuth and elevation) between corresponding aircraft. Atmospheric transmissivity, background clutter, and ownship IR sen- sor sensitivity are also taken into ac- count.

As part of the simulation environ- ment, air-to-air weapon delivery and fire/weapon control are accomplished through algorithms that simulate AMRAAM, SIDEWINDER, and SPARROW missile flyouts, and guns. These routines, which were ac- quired from Perceptronics Incorporated, have been verified and validated by the Air Force and the Navy on ACMR ranges.

An extensive early warning and ground controlled intercept simulation or Electronic Order of Battle (EOB) was derived from a Northrop analytical non- real-time ground-based air defense simulation called FLEXNET. EOB provides a representation of the elements, func- tions, and interfaces that exist in an actual air defense system. An approxima- tion of the behavior of a specific defense system is achieved by assigning appropriate values to key parameters such as processing update rates and descriptors representing capabilities of various system elements. EOB is com- prised of

o a single comman control/ 4/ communication (C ) center handling weapon allocation and control;

o a network of early warning (EW) radar sites;

o a network of surface-to-air missile (SAM) sites;

o a Fire Control Radar (FCR) ; o ground control intercept

(GCI) stations with air in- tercept vectoring;

o simulated SU/AWACS and com- puter controlled aircraft.

This model can be assigned to either the Red or Blue teams. SAM and FCR sites are displayed on the "God's- Eye-View1#. If, for example, EOB is as- signed to the Red team, Blue members will see on their avionics displays oc- casional radar strobes from the ground- based radars1 attempt to establish track. If a target track is made, the C 9 logic will assign either a SAM site or an airborne interceptor to attack the threat. Blue avionics displays will in- dicate a SAM site's radar lockon and missile launch, and will provide infor- mation on the direction of the inbound missile. SAM altitude exclusion zones can be established to protect friendly air interceptors that are directed to airborne targets from being fired upon. These interceptors can also receive steering cues, shown on the MICS dis- play, that are transmitted from simu- lated ground control intercept (GCI) stations directing the pilots along an intercept course with the threat aircraft.

Computer controlled aircraft are currently being used to simulate certain interactive participants for some mis- sions. These aircraft have been con- figured to simulate such varying mis- sions as a Red or Blue AWACS, a Red fighter with limited detection and mis- sile firing capability, or a Blue striker penetrating hostile territory to bomb a target. An effort is underway to integrate the TAC BRAWLER pilot model to enhance the ability of these computer driven participants. As mentioned pre- viously, to augment the number of par- ticipants available in the simulation, regeneration of aircraft is possible after a "killI1 occurs. The test director selects, from one of the pages on his simulation control display, one of several predefined points in the battle area where he wishes to regenerate a particular 'ldead1I player. A fresh com- pliment of fuel and weapons is provided to that pilot. This regeneration feature can be used at any time, whether or not a player is dead.

Simulation Initialization and Monitor

ISSL has developed an efficient and flexible simulation initialization func- tion that modifies the load module data base variables and constants to satisfy the simulation run scenario. With menu driven software, these values can be

modified quickly between simulation tri- als causing no delay. The data flow diagram in Figure 8 describes this process. Aircraft types can be predefined in terms of such parameters as airframe/performance vehicle, avionics suite, RCS and IR signature pattern, weapons load, and team and mem- ber number. However, any data value can be examined individually and modified. A variety of desired scenarios can be cus- tom built from the various initializa- tion parameters and stored as data files for later use. These parameters include aircraft start geometries (latitude, longitude, and altitude locations in in- ertial space), force mixes, combat air patrol (CAP) point and waypoint loca- tions, and weather effects on sensors and missiles.

The EOB model is initialized from trial to trial in a similar fashion. This menu driven software initialization routine allows quick modification of parameters in order to represent ex- pected EOB capabilities of either team. For example, SAM and FCR site types and laydowns are stored for a variety of scenarios and can be called up between trials. Other EOB initialization fea- tures include the selection of RCS pat- terns at different polarizations, frequencies, and decibel gains that will simulate the signature of threat aircraft as seen by the ground-based radars.

As part of the simulation monitor- ing function, data collection and reduc- tion is available in many forms. Real- time event-based data is collected for significant events occurring during the

course of a trial. Time-based collection of aircraft state variables, avionics modes, sensor positioning, and other pertinent information is used to playback the engagement in non-real- time. In this way pilot decisions and strategies can be evaluated. Question- naires concerning human factors deci- sions are answered by the pilots in real-time at the MICS using the touchscreen to input answers. Quick- look data displayed on a CRT terminal can assess the outcome of the battle at a glance indicating who died and how. Data is stored on the hard disk for later print-out or for transfer to mag- netic tape for data analysis at another location. Examples of the type of output derived from some these multiple- engagement simulations is shown in Figure 9.

Extensive data collection and reduction capabilities allow large quan- tities of results to be obtained. Those results permit the evaluation and validation of aircraft and system designs before an expensive commitment to hardware is made. In addition, by performing integration and checkout of point designs early in the aircraft sys- tem development cycle, costly mistakes can be avoided.

Simulation Real-Time Execution

From Figure 10, it can be seen that the simulation real-time executive software manages the load module scheduling. It also provides the inter- facing between the domes, MICS, display graphics, and data recording hardware. Much of the system software for schedul-

1 S IMULATION M O D E L I N G I

DATA BASES AND LOAD MODULES

Test Scenar~o fMlss~on Spec f~c Data1 Vsual Dlspiay Data A r Vehicle Data Datapool and Global Data Avlon~cs Data Environmenia Data Slgnal Conversfo? Data Slmulaton Load Modules

SIMULATION INITIALIZATION A N D MONITOR

SYSTEM INITIALIZATION FUNCTIONS

B u ~ d Load Module Data Base Load Datapool . Provlde Smulallon Load Modules for Each Processor Initfailre Each Processor . Download Processors

MAN-MACHINE INTERFACE FUNCTION

Provlde Menu Drlven Prompts t o D e f ~ n e

Hardware Test Scenarlo Weapons and Threats Aircraft Def\%tions - A~rcraft Types - ICS Slrnulators - Dome Srnulators - F g h l QuaI111es - Weapons

Eectronlc Order of Bat:le Inli~al~Zdllon

Event Based Data Recordng . T~me Based Data Recordng

P o l Ouestonnare Data Recordnrj

ReaiTime Debug Analys~e

Post F g h t Smua t~on A n a v w

BATTLE SITUATION ROOM FUNCTION

/ 4 S~muiatlon Control I

TEST ENGINEER'S I I I STATION FUNCTION 1 W Data Montorng

Test Setup and Control Graohcs Dlsoavs Sirnulaton Control Functions

I PROCESSOR D O W N L O A D + +

I SIMULAT ION REAL-TIME EXECUTION

Figure 8. Simulation Initialization and Monitor

141

FIGHTER VS. FIGHTER EXCHANGE RATIO

(I) W

ln rJ) I 3

AIRCRAFT CONCEPT A

AIRCRAFT CONCEPT B

AIRCRAFT CONCEPT C

MISSILE 1

MISSILE 2

MISSILE 3

--

TECHNOLOGY

(a)

TRADE STUDY EXAMPLE

TARGET DISTRIBUTIONS

LONG RANGE SHORT RANGE

TECHNOLOGY TRADE EXAMPLE

SYSTEM SITUATION AWARENESS 0 - POSTPROCESS ANALYSIS

I DUAL HYPOTHETICAL TRIPLE HYPOTHETICAL SENSOR OPTIMAL SENSOR SENSOR OPTIMAL SENSOR SYSTEM MANAGER SYSTEM MANAGER

(b)

PILOT PROFICIENCY ANALYSIS

OFFENSIVE POTENTIAL 1 SURVIVABILITY

Figure 9. Typical Simulation Results

ing the real-time tasks, downloading of software modules, sending messages, and so forth is developed in-house to better accommodate the unique hardware and software schemes used in the laboratory. System library routines supply the in- terface between the simulation hardware network and the multitude of 1/0 devices (digital-to-analog or analog-to-digital converters and real-time peripherals) to transform discrete signals. This type of programmable software switching between digital and electrical lines permits the rapid interchangeability of cockpits and the reprogramming of MICS joystick and touchscreen switchology to meet any project s needs.

SIMULATION PROCESSORS

The processing power behind the real-time simulation incorporates four coupled Gould Concept 32/9780 processors as the primary computing device. The Gould processors control the overall simulation, including the domed simulators and the MICS. The Gould Con- cept 32/9780s are 32-bit word minicom- puters containing a central processing unit (CPU) and a closely coupled multi- processor internal processing unit (IPU). The IPU does not perform any 1/0 or interrupt functions, but executes any

other instruction type in parallel with the CPU. Both the CPU and the IPU have 32 kilobytes (kb) of cache memory, 256 kb of shadow memory. The two processors share four megabytes (mb) of additional memory. The maximum throughput rate of the 1/0 system is 26.7 mb per second. The maximum instruction execution is rated at 10 million instructions per second (mips) per Gould 32/9780. All software is run in a 50 millisecond frame time and is primarily developed in the FORTRAN language. Two of the four Gould 9780s communicate with each other through one megabyte of shared common memory. In addition, the four systems are tied into one megabyte of facility shared memory.

In the current configuration, one pair of Gould 32/9780s does the avionics and airframe processing for the Dome 3 simulator, the simulation control dis- plays for the TES and TDS, the Compus- cene I11 interface, the data reduction, the electronic order of battle, the mis- sile flyout and scoring algorithms, and the IR sensor modeling. The other pair of primary 9780s computes the displays and avionics for the seven MICS, the "Godls-Eye-View1* and the parametric data displays, and controls the audio between participants. When Dome 1 is used in the large air combat simulations, two addi-

I SIMULATION INITIALIZATION A N D MONITOR

PROCESSOR D O W N L O A D

S IMULAT ION REAL-TIME EXECUTION

SYSTEM EXECUTIVE FUNCTIONS

Load Module Scheduling 110 Devce Drlver Routnes

System Llbrary Routlnes Simulation Control

BATTLE SITUATION ROOM ri FUNCTION 1

tional Gould 9780s are interfaced into the simulation via a Gould-to-Gould High Speed Data (HSD) link. The HSD link is used in this case because of the restriction on large distances in the shared memory between computers. The Dome 1 9780s host that simulatorls avionics, airframe, and the interface to the Compuscene IV. Software routines and data pertinent to all participants reside within the primary set of four Goulds. The philosophy here is to avoid running duplicate software, and thus all datapool or global variables are passed over the link.

Out of Cockp~t Dlspays Prolector Drlve Roul~nes Ground and Sky Scenes D~splays of - Targets - M ~ s s e s - Other A~rcraft

The vehicle dynamics, equations of motion, and relative geometry are com- puted in a Floating Point Systems' 5320 array processor hosted to each pair of Gould 9780s. The maximum instruction ex- ecution rate on this processor is 20 mips.

9 Slgnal Convers~on . Fllght S~mulat~on Raster Graphics Table -Load Modules Dsplays Convert DIA and AID for Each C*

In Cockp~t Dsplays Route Data to F g h t S~mulat~on Functions

MICS Drivers -Load Modules

Accept Data from God s Eye Vew

Cockp~t S~mulations Return Data to Touch Screen Control

Cockp~t Dr~vers Vector Graphcs Displays

As mentioned earlier, the back- ground scene generated by the General Electric Compuscene I11 system for Dome 3 is driven by two Gould 32/9750s. The Gould Concept 32/9750 is identical to the 32/9780, except there is only one central processing unit (CPU) and no parallel internal processing unit (IPU). These two machines are interfaced to one of the primary set of four Goulds through an HSD inter-bus link (IBL). The Compuscene IV (driven by one 32/9780) is connected to the Dome 1 pair of Gould 32/9780s through the same type of HSD IBL.

A

COCKPIT ASSEMBLY FUNCTIONS

Graph cs D splays Control Self ngs Plot Interface

Figure 10. Simulation Real-Time Execution

MICS SIMULATORS FUNCTIONS

Graphics Dlsplays

Control Settngs

The processors driving the color raster MICS, simulation control, "God's- Eye-View", and parametric displays are provided by ADAGE 3000 graphics. The cockpit head-up and head-down displays in both domes can be generated with ADAGE 4135 monochromatic stroke graphics. Currently, color raster head- down displays are being integrated into an advanced cockpit for Dome 3. The Silicon Graphics 4D/70GT is the graphics processor being used to generate these displays.

FUTURE ENHANCEMENTS

Large air combat simulations cur- rently use six Gould 9780s and three FPS 5320 array processors to model nine aircraft, their avionics systems, and the threat environment. This computation effort does not include the processors used to generate the two dome background scenes. Some simulations have saturated this computing capacity due to the com- plexity of the models required and the number of aircraft involved. The Adage 3000 color raster graphics processor requires a certain amount of Gould processing for display formatting. Hence, when all seven MICS are used along with the wGodfs-Eye-Vieww, parametric, and simulation control dis- plays, this puts an added computational burden on the host Gould machines.

Any expansion to add more participants 1s not possible with this configuration.

The following enhancements are cur- rently being implemented to accommodate an expansion and enhance computing capacity:

1. Each existing MICS will be front- ended with a Gould Concept 67 Micro-Sel computer which contains a CPU and an IPU. All the avionics, sensor models, and controls and display formatting that is currently done on the host Gould com- puter will be moved to each individual station's processor.

2. Additional MICS will be added in the near future to meet expanding project requirements. The graphics processor of each of these new stations will be the Silicon Graphics 4D/70GT. Each new MICS will be front-ended with a Gould Micro-Sel. The current configura- tion, plus the new enhancements is shown in Figure 11. The new stations will mainly be used as Blue participants which tend to have more complex dis- plays. This approach will ensure com- patibility with the Silicon Graphics

FIXED-BASE VISUAL FLIGHT

SIMULATOR DOME 1

I COCKPIT - - - -

ASSEMBLY HARDWARE IIF PROJECTION AND CGI IIF rl I c o c T IIF I

2 GOULD 32197s ARRAY PROCESSOR I

displays generated for the Dome 3 cock- pit, also a Blue participant. In order to maintain flexibility for the many programs that are using the facility, these new stations can be Red if a project desires. The video outputs of all the stations will be common (1024 lines) so that one large video distribu- tion system is all that is required to display repeaters at the TDS and TES and record the desired channels.

3. The Red and Blue teams will be given separate brief/debriefing facilities, seen in Figure 12. The MICS will be isolated from one another by locating each station within a small room to avoid intra-aircraft communica- tions from being overheard. The emphasis on flexibility is carried over here by the ability to isolate Red and Blue players for any force mix required using a movable partition. Current plans are to have eleven MICS operational in the near future, though the facility is designed to house sixteen stations for a total number of participants of eigh- teen.

\\ FIXED-BASE

) DOME 3

AND CGI IIF COCKPIT IIF

COMPUSCENE

I_ 1 I 2 GOULD 32197s I 2 GOULD 32197s ARRAY PROCESSOR

I I I I I I I

HIGH-SPEED DATA BUS

HIGH-SPEED DATA BUS HIGH-SPEED DATA BUS

I I 4 MANNED I 7 MANNED

I INTERACTIVE CONTROL I INTERACTIVE CONTROL STATIONS

I FUTURE 1

I I I I I I I I i 1 : 4 G O U L ~ I C R O S E L S 41 1 M;ROsELs 1 1 I 4 SILICON GRAPHICS 7 ADAGE 3000 GRAPHICS

I I I I I

I I I ' REFLECTIVE MEMORY I REFLECTIVE MEMORY I

SHARED MEMORY 1 GOULD 32197 SHARED MEMORY 1 GOULD 32197 ARRAY PROCESSOR EXECUTIVE CONTROL

TEST ENGINEER'S STATION (TES) COMPUTER OPERATIONS ROOM

TEST DIRECTOR'S STATION (TDS) BATTLE SITUATION ROOM (BSR)

Figure 11. ISSL Current and Planned Hardware Configuration

Battle Participants' Area

Figure 12. Battle Participants' Area

4. The cockpit assemblies in both domes are to be interfaced with Computer Products Incorporated's Advanced Simulator Linkage System (ASLS). Stand- alone, this system is run from an IBM PC and performs intelligent 1/0 to inter- face any cockpit assembly with Gould, VAX, Harris, and other computer systems. The design and check-out of analog, dis- crete, and custom interfaces between switches and displays of a cockpit as- sembly can be done at remote sites before integration and installation into the ISSL domes through a high speed data (HSD) link. The advantage of the ASLS is its remote processor's ability to per- form internal conversions of analog, digital, discrete, and ASCII signals, and conduct diagnostics using vendor supplied maintenance software.

ACKNOWLEDGMENTS

I would like to extend my sincere appreciation to those individuals, too numerous to name, who provided ideas and assisted in the proof-reading of this paper. I especially applaud those per- sons, past and present, who have con- tributed in all aspects to the success of the multiple-engagement simulation with their ingenuity, hard work, and dedication.

REFERENCES

1. Perkins, J.A., Passmore, H., ''Advanced Medium Range Air-To-Air Missile (AMRAAM) Manned AIr Combat Simulation (MACS) Operational Utility Evaluation (OUE) , McDon- nell Douglas Corporation, Final Report For Contract F29601-80-C- 0044, 31 August 1982.

2. User Operating Manual For Air Com- bat ~aneuvering Range AN/USQ-T2 (U), Cubic Corporation, Contract Number N00019-71-C-0429, 15 August 1974.