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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
