Precise orbit determination with the DORIS/SPOT2 system: First results
Abstract
One of the main challenges of the French/U.S. oceanographic mission, TOPEX/Poseidon, is the need to determine the position of the spacecraft with an accuracy of 10 cm in the radial direction after 10 days. In order to reach this level of accuracy, a tracking system, Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS), was developed. This system is composed of a network of about 40 dual frequency beacons scattered all over the world and a receiver on board a spacecraft. The spaceborne processor integrates the Doppler shifts over 10 second intervals and downloads the results and the measurements time tags to the ground control center. An orbit determination software, ZOOM, was developed to generate precise orbits. This program has the capability to process the DORIS data type in addition to all other conventional measurements. As a proof of concept and feasibility test, the first DORIS receiver was placed on the SPOT 2 Earth observation satellite. The whole system (hardware and software) has worked successfully since Feb. 1990, enabling the routine computation of the orbit of SPOT 2 for more than one year. An overview of the orbit production process including the operational set up and the dynamical and measurement models is presented. The orbit quality assessment procedures are described and the ability to ensure the consistency of the system in spite of the large number of independent oscillators, is demonstrated.
- Publication:
-
ESA Special Publication
- Pub Date:
- December 1991
- Bibcode:
- 1991ESASP.326...91N
- Keywords:
-
- Computer Programs;
- International Cooperation;
- Orbit Calculation;
- Satellite Tracking;
- Spot (French Satellite);
- Systems Engineering;
- Communication Networks;
- Data Processing;
- Doppler Effect;
- Position (Location);
- Radio Beacons;
- Astrodynamics