Doris
Principle.
System.
Doris applications.
doris missions.
Doris-equiped satellites
The Doris system has been a great technical, operational and scientific success. The Doris instrument, which is already flying on a number of satellites and is being considered for several new missions, guarantees users a high-quality operational service providing precise orbit determination over the long term. With more satellites carrying the Doris instrument, the system will make more accurate than before.
Current on-orbit constellation
Currently five Doris contributor satellites are in flight, and their measurements are available at the IDS data centers.
- Spot-4 (Cnes) was launched in 1998, and is expected to continue until 2012. Further information on on the Cnes Space Scientific Missions website.
- Jason-1, the Cnes/Nasa Topex/Poseidon follow-on mission was launched on December 7, 2001 with a miniaturized second generation Doris receiver, a GPS and LRA localisation system. Due to the South Atlantic Anomaly (SAA) effect on the Jason-1 on-board Ultra Stable Oscillators (USO), a correction model has been developed:
by J.M. Lemoine and H. Capdeville (J. Geodesy, 2006) and is available on IDS website.
Further information on Jason-1 mission. - Envisat (ESA) was launched on March 1, 2002 with a second generation Doris receiver and a laser retroreflector array (LRA). Further information on Esa website.
- Spot-5 (Cnes) was launched on May 4, 2002 with a miniaturized second generation Doris receiver. The mission should be extended to 2015. Further information on on the Cnes Space Scientific Missions website.
- OSTM/Jason-2 (Cnes/Nasa/Eumetsat/Noaa) - The Topex/Poseidon and Jason-1 follow-on ocean observation mission was launched on June 2008. Jason-2 takes on board the new DGXX Doris receiver (7-channels: beacons simultaneous tracking capability has been raised up to seven beacons, USO new generation allowing a better frequency stability while crossing SAA, a better quality of MOE and Jason-2 useful for beacons location), and LRA and GPS as tracking systems. Further information on OSTM/Jason-2.
From June 2008 to end of January 2009, both Jason-1 and OSTM/Jason-2 satellites were on the same orbit with a one minute shift. Then, thanks to five orbit change manoeuvers peformed between January 26th 2009 and February 14th 2009, Jason-1 is now located in an interleaved orbit with respect to Jason-2, with a time lag of approximately 5 days. This new tandem configuration is better suited for real-time applications.
Satellites | Doris receiver generation | Doris redundancy | Other tracking system | Cospar # | Doris instrument end |
|---|---|---|---|---|---|
1G | No | - | 9000501 | 30-Jun.-2009 | |
1G | Yes | SLR+GPS | 9205201 | 1-Nov-2004 | |
1G | No | - | 9306101 | 9-Nov-1996 | |
1G | No | - | 9801701 |
| |
2GM | Yes | SLR+GPS | 0105501 |
| |
2G | Yes | SLR | 0200901 |
| |
2GM | No | - | 0202101 |
| |
CITRIS | - | GPS | 0700604 |
| |
DGXX | Yes | SLR+GPS | 0803201 |
Confirmed future Doris missions
The future Doris missions are numerous and should guarantee a constellation with at least four Doris contributor satellites through 2020:
- Cryosat-2 (ESA) is to be launched in February2010 with on board a Doris DGXX Receiver + LRA, (3.5 years as nominal lifetime). Further information on Esa website.
- HY-2A (China Academy of Space), is to be launched by the end of 2010, with on board a Doris DGXX + LRA + GPS (nominal life time of 3 years). Further information on HY-2A mission.
- Saral (Isro/Cnes) is to be launched from September 2010, with a Doris DGXX + LRA (nominal lifetime of 5 years). Further information on Saral.
- Sentinel-3A (GMES/ESA) is planned for April 2013 (DORIS DGXX + LRA + GPS) (nominal lifetime of 7 years), Then sentinel 3B is planned for 2017. Further information on Esa website.
Proposed future missions or missions awaiting approval
- Jason-3 (Eumetsat/Noaa/Cnes) pending approval before end of 2009, is foreseen from mid 2013 (DORIS DGXX + LRA + GPS). Further information on Jason-3.
- Swot (Surface Water Ocean Topography) Mission is foreseen for end of 2016 (DGXX + GPS + LRA). Further information on Swot website or on Aviso website.
- HY2 Missions and Doris on board are pending approval: HY-2B 2012, HY-2C 2015, HY-2D 2019: DORIS + GPS + LRA. Further information on HY-2A.
- Sentinel 3, C, D with DORIS+GPS+LRA from 2021: to be confirmed. Further information on Esa website.



