Introduction-of-GNSS-2

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Transcript of Introduction-of-GNSS-2

GNSS Surveying (GE 205)

Kutubuddin ANSARIkutubuddin.ansari@ikc.edu.tr

Lecture 2, March 1, 2015

Introduction to GNSS

GLONASS

GLObal NAvigationSatellite System, Russia

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Introduction to GLONASS

Russian satellite navigation systempositioning by measuring distances to satellites with known positions

• First launch in 1982• Complete constellation in 1996 • Modernized Glonass-M and new Glonass-K • Next launch: 25 December 2005 (3 Satellites)• 18 operational satellites in 2007• Present constellation (24) satellites

GLONASS Integration

Advantages• Improved precision• Improved reliability and integrity• More flexibility in positioning

GLONASS Space Segment

GLONASS GPS

24 satellites 24

3 orbit planes 6

64,8° inclination 55°

11h16m orbit period 11h58m

1998

GLONASS Control Segment

Main taskpredict satellite orbits and clock behavior

ComponentsSystem Control Center

planning and coordination of activitiesPhase Control System

monitor satellite clocks by comparing satellite signals with system timeTelemetry, Tracking and Command Stations

computation of satellite orbits by radar distance measurement, communication, control segment for the satellites,monitoring of satellite signals

GLONASS Control Segment

Telemetry, Tracking and Command stations

Because of the geographic location of TT&C stations it is system integrity is difficult to maintain

Komsomolsk

Jeniseysk

RUSLANDGolitsino

St. Petersburg

GLONASS User Segment

Development of user segment• GLONASS in 1993 released for international civil use• “all-in-view” single frequency receivers available since 1996• “all-in-view” dual frequency receivers available since 1998

Receiver manufacturersAshtech, JPS/TPS, 3S Navigation (single & dual freq.)Novatel, MAN Technologie, Zeiss, Dasa (single freq.)

European Geostationary Navigation Overlay Service

(EGNOS) and Galileo

The Structure of EGNOS and Galileo

• European Geostationary Navigation Overlay Service• Search for a system started in 1995• Developed the framework for EGNOS• EGNOS went into operation in 2004• EGNOS technology will be integrated into Galileo

in 2006-2008.• Precursor to Galileo• Enhances GPS/GLONASS

Why was it developed?

• As opposed to GPS, which was developed primarily for military uses, Galileo was developed exclusively for civilian use.

• There are zero militarily uses for Galileo as of right now, and no plans for military use in the future.

Space Segment

• Contains a total of 30 satellites; 27 are operational • 3 spare satellites • Satellites are in 3 different planes, equally spaced

around the plane. • Altitude = 23, 600 km• Satellites are in Medium Earth Orbit (MEO)• 3 Geostationary Earth Orbiting (GEO) satellites.

Space Segment

• Each satellite has a period of 14 hours and 22 minutes

• Each satellite can last for 20 years, although they may be replaced every 12 years

• At any point on earth, at least 6 satellites will be in view.

Control Segment

• 4 Mission Control Centers which contain a Central Processing Facility (CPF)

• 34 Ranging and Integrity Monitoring Stations (RIMS)

• 6 Navigation Land Earth Stations

Control Segment

• Mission control - maintains the management of satellite clocks

• Satellite control - monitors if the satellite orbits are on path

User Segment

• Consists of one of two receivers; one that uses GPS or one that uses GLONASS.

• EGNOS is also programmed into that receiver.

• EGNOS helps sharpen the receiver’s position from 20 meters of error to as little as 5 meters of error.

COMPASS BeiDou Navigation Satellite

System (BDS), China

COMPASS

Constellation

GEO (Geostationary Earth orbit) Satellite

MEO ( Medium Earth Orbit) Satellite

Space Segment

5 GEO satellites and 30 Non-GEO satellites

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The ground segment consists ofo Master Control Station, o Upload Stations and o Monitor Stations.

Control Segment

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The user segment consists of BeiDou user terminals and interoperable terminals with other GNSS.

User terminals of BeiDou system

User Segment

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Deployment Step

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o 3 GEO satellites has been launched since 2000 to 2003

o The demonstration system is able to provide basic services including positioning, timing and short-message communication in regional area.

o Currently, all the 3 satellites work normally in orbit.

Oct 31,2000 Dec 21,2000 May 25 ,2003

The first MEO satellite named COMPASS-M1 was

launched in Apr. 2007 which secured the time related

filing. Many technical experimentations have been

implemented using COMPASS-M1.

COMPASS-M1 Launch

COMPASS-G2 Launch

The first GEO satellite named COMPASS-G2 was launched from the Xichang Satellite Launch Center on Apr.15 2009. The GEO navigation satellite related technologies have been verified using the satellite.

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GEO Satellite Launch Latterly

The 3rd satellite of BeiDou was launched from the Xichang Satellite Launch Center on Jan.17 2010. The satellite is also the 2nd

GEO satellite.

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BeiDou started to

cover Asia-Pacific area from around 2012, and will cover all over the

world before 2020.

Deployment Step

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Applications

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BeiDou Navigation Demonstration System has played important roles in various areas.

- Surveyi and mapping- Communication- Water conservancy- Disaster mitigation- Marine- Transportation- Mining- Forest fire rescue- etc.

Indian Regional Navigation Satellite System (IRNSS), India

•IRNSS Refers to Indian Regional Navigation Satellite System implemented by the Indian Space Research Organization (ISRO)

•IRNSS is an independent Navigation Satellite System providing Navigation services in the Indian Region.

•IRNSS system provides the user with a targeted position accuracy of better than 20m over India and the region extending to about 1500 km around India.

IRNSS Objective

•Consists of 7 Satellites, 3 in Geo-Stationary orbit at 32.5°,83° and 131.5° East.

•4 Satellites in GEO Synchronous orbit at inclination of 29° with Longitude crossing at 55° and 111.75° East.

• The full constellation started to operate from 2015

Space Segment

Space Segment

Control Segment

The user segment consists of IRNSS receivers operating in

Single Frequency ReceiverDual Frequency Receiver

User Segment

Quasi-Zenith Satellite System (QZSS) , Japan

QZSS•The Quasi-Zenith Satellite System (QZSS) developed by Japan Aerospace Exploration Agency (JAXA) is a regional navigation satellite system.

•Which is used as a constellation of satellites placed in Highly-inclined Elliptical Orbits (HEO).

•A highly elliptical orbit (HEO) is an elliptic orbit with a low-altitude (often under 1,000 kilometers) perigee and a high-altitude (often over 35,786 kilometers apogee).

•This is to ensure that one of the satellites is always visible near zenith over Japan, including in urban and mountainous areas whereby it is difficult to receive GNSS signals.

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Overview of QZSS

Objective• GNSS complementary• Improve availability • Improve accuracy

First QZSS Satellite • First Launched in September 2010

Future QZSS Satellites:• 2 HEO and 1 GEO End of March 2018

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Space Segment

Satellites will become 4

3 (Highly Elliptical Orbit (HEO)1 Geostationary Earth Orbit (GEO )

Coverage Area (East Asia and Oceania)

RMIT University PPP Workshop 2013, Ottawa 41

Ground Segment

• Monitor test station (9 overseas and domestic stations)• Master Control Station (in Tsukuba)

• Time control test station (in Koganei and Okinawa)• QZS tracking and control station

Projects

1. Monthly Ionospheric Error and its comparison during quiet and storm days for diurnal variation

2. Ionospheric Error and its comparison with International Reference Ionosphere (IRI) model buy using cross correlation coefficient.

3. Tropospheric Error and its relation with temperature

4. Triangular affine transformation from ITRF to local datum and barycentric coordinate

5. Dislocation Modelling of the high-precision Global Positioning System displacements