DORIS - DAYS Toulouse May 2-3, 2000
DORISDORIS
Doppler Orbitography and Radiopositioning Doppler Orbitography and Radiopositioning Integrated by SatelliteIntegrated by Satellite
Basic system concept
Main missions
Schedules
Conclusions
DORIS - DAYS Toulouse May 2-3, 2000
Satellite with DORIS instrument
B.O. :
Orbitography Beaconof the permanent system network
(Quartz USOPrecisely positionned
meteo data and beacon status transmission)
B.M. : Master Beacon
(B.O.+
System timeand frequency references
+Instruments control
&
mission uploading)
DORIS Mission and System Center
Users Beacons NETWORK
B.C. : Customer Beacon to be positionned
(idem B.O.can be field packaged)
DORISDORISsystem Overviewsystem Overview
DORISDORISsystem Overviewsystem Overview
B.O.T. : Time reference and Orbitography Beacon
DORIS GROUND SEGMENT
DORIS - DAYS Toulouse May 2-3, 2000
DORIS/SPOT 2 1990DORIS/TOPEX 1992DORIS/SPOT 3 1993DORIS/SPOT 4 1998DORIS/ENVISAT Mid 2000DORIS/JASON End 2000DORIS/SPOT 5 2001
DORISDORIS
Space segmentSpace segment
DORIS - DAYS Toulouse May 2-3, 2000
Main missionsMain missions
Precise orbit determination for Topex/Poseidon and Jason:
Altitude of Topex/Poseidon accurate to within three centimetres, on radial component in support to scientific (altimetry) mission performance
Jason to provide centimetre accuracy
Accurate location of ground beacons to establish and maintain the terrestrial reference system
used for altimetry measurements for geodetic and geodynamics applications
Accurate autonomous navigation capability Models improvements:
gravity field, air drag, ionosphere, troposphere.
DORISDORIS
DORIS - DAYS Toulouse May 2-3, 2000
Main missionsMain missionsOrbit determination (1/2)Orbit determination (1/2)
Doris was originally designed for precise orbit determination in support of altimetry satellite missions:
within 5 cm for Spot 2 3 cm for Topex radial component Objective of 1 cm for Jason, thanks to
improved gravitational models and cross utilization of other geodetic technics (GPS, Laser, …).
DORISDORIS
DORIS - DAYS Toulouse May 2-3, 2000
Main missionsMain missionsOrbit determination (2/2)Orbit determination (2/2)
Real time navigation: Thanks to on-board measurement processing by DIODE
software (included in Doris software), and demonstrated in Spot 4,
Less than 30 cm rms 3 axes achievable on Jason, Time synchronisation: 3 micro seconds wrt TAI or UTC
time scale.
Location station calibration (radar, 2 GHz networks)
Precise estimation of altitude control thruster efficiency (Spot)
DORISDORIS
DORIS - DAYS Toulouse May 2-3, 2000
DORIS PERFORMANCEDORIS PERFORMANCEOrbit determination missionOrbit determination mission
DORIS orbit determinatio
nproducts
Accuracy Turnaround Application
Initial orbit 10 centimetres 48 hours
Satellite operation
Precise orbit 3 centimetres 1 month
• Processing of satellite altimetry measurements• Calculation of manœuvre efficiency• Calibration of other measurement systems (radar, 2GHz location, etc.)
Onboard real timePrecise Doris (Jason)Single-frequency Doris(navigation)
<1 metre
10 metres
Immediate• Satellite autonomy• Auxiliary data for satellite payload
Delayedtime
(ground)
Realtime
(onboard)
DORIS - DAYS Toulouse May 2-3, 2000
DORISDORISDORISDORIS
Geodesyaccurate absolute and relative location
Geodynamicsplate tectonics
Volcanologysurface deformation monitoring
Glacier monitoring Landslide monitoring Construction and monitoring of large civil
engineering structures
Main missionsMain missions
LocationLocation
Main missionsMain missions
LocationLocation
DORIS - DAYS Toulouse May 2-3, 2000
DORISDORISDORISDORIS
Precise point positionning Doris provides fast data on ground beacons
positions;
The CLS company provides Doris services on an operational, commercial basis:
precise point coordinates at remote locations: islands, platforms, secondary reference points, etc.
tying local geodetic networks into reference networks,
long-term measurement of geodynamic drifts,
remote monitoring of natural hazard areas(e.g., seismic zones, volcanoes, landslides).
Geodetic applications (1/2)Geodetic applications (1/2)Geodetic applications (1/2)Geodetic applications (1/2)
DORIS - DAYS Toulouse May 2-3, 2000
DORISDORISDORISDORIS
Earth Rotation Doris provides
Earth rotation parameters with a one-day resolution, used to study of dynamic interactions between fluid and solid Earth components.
Earth Center position
Geodetic applications(2/2)Geodetic applications(2/2)Geodetic applications(2/2)Geodetic applications(2/2)
Source IERS DORIS
DORIS - DAYS Toulouse May 2-3, 2000
DORISDORISDORISDORIS
Doris was accepted in 1994 as a new technique of the International Earth Rotation Service.
IERS objectives include the establishment and maintenance of a high accuracy Earth reference system.
Doris contributed to ITRF 94, 96, 97 and will contribute to ITRF 2000.
Because of its performances, the international community proposed to create an International Doris Service at the last general assembly of the IGGU (July 1999).
Reference systemsReference systemsReference systemsReference systems
DORIS - DAYS Toulouse May 2-3, 2000
DORISDORISDORISDORIS
Doris can be used to measure tectonic plates relative motions of the terrestrial lithosphere;
Measurement accuracy allows validation of cinematic models and determination of local phenomena.
GeophysicsGeophysicsGeophysicsGeophysics
DORIS - DAYS Toulouse May 2-3, 2000
DORIS PERFORMANCEDORIS PERFORMANCEDORIS PERFORMANCEDORIS PERFORMANCEGround beacon locationGround beacon locationGround beacon locationGround beacon location
Results within 2 or 3 daysOperational geodesy
(1 m to 15 cm over 1 day)
Results within 1 week
Results within a few monthsHigh precision geodesy
(10 to 0.1 cm over 1 year)Altimeter reference
Measurements, In days
2-
3-
20 cm
10 cm
0 cm
1 2 5 10 30
1-
DORIS - DAYS Toulouse May 2-3, 2000
DORISDORISDORISDORIS
Improvement of the Earth gravity field;
Global ionosphere mapping for radio-electric signal propagation error correction;
Calibration and validation of other space geodesy techniques.
Other DORIS applicationsOther DORIS applicationsOther DORIS applicationsOther DORIS applications
DORIS - DAYS Toulouse May 2-3, 2000
DORISDORISGeneral scheduleGeneral schedule
DORISDORISGeneral scheduleGeneral schedule
Earth rotationEarth rotation NavigationNavigation Gravity fieldGravity fieldAccurate locationAccurate locationPrecise orbitPrecise orbit
90 91 92 93 94 95 96 97 98 99 2000 01 02 03 04
Topex-Poséidon
Envisat 1
Pleïade
Spot 2
Spot 3
Spot 4
Spot 5
Jason 1
DORIS - DAYS Toulouse May 2-3, 2000
MassMass20 kg
10 kg
DORISDORIS Instrument evolutionInstrument evolution
DORISDORIS Instrument evolutionInstrument evolution
DataData1980 200019900
1st generation, Spot 2, 3 and 4, Topex/Poseidon
No redundancy
2nd generation, Envisat
No redundancy
2nd miniaturized generation, Jason, Spot 5
No redundancy
miniaturized generation
Mass produced
DORIS - DAYS Toulouse May 2-3, 2000
DORIS PERFORMANCEDORIS PERFORMANCEDORIS PERFORMANCEDORIS PERFORMANCEGround location beacon evolutionGround location beacon evolutionGround location beacon evolutionGround location beacon evolution
MassMass
3rd generation, enhanced performance,
DateDate1980 20001990
20 kg
10 kg
0
1st generation, 50 GLBs produced
2nd generation 25 GLBs produced
DORIS - DAYS Toulouse May 2-3, 2000
The Doris accurate location system provides outstanding performance.
It has been constantly improved since it became operational in the early 90’s and additional improvements are already planned for the next ten years.
It will continue to complement existing GPS, VLBI and SLR systems and at the same time it will provide unique capabilities such as:
a worldwide ground network, precise measurements of vertical crustal movements (better
than 1 mm/year) presice measurement of temporal variations of geodetic
parameters (geocenter movement).
ConclusionsConclusionsConclusionsConclusions