DORIS is a Doppler satellite tracking system developed for precise orbit determination and precise ground location. It is onboard the Jason-1 and ENVISAT altimetric satellites and the remote sensing satellites SPOT-2, SPOT-4 and SPOT-5. It also flew with SPOT-3 and TOPEX/ POSEIDON.

Principle: How does Doris work? The Doris system is based on the principle of the Doppler effect. It is a system optimized for orbit determination with extreme precision, global coverage and all-weather measurements.

System: Details on Doris instrument which is part of the satellite payload, on terrestrial stations, on control and processing center and on system enhancements.

Doris applications: In addition to its functions in orbitography, Doris as a space surveyor is also a terrestrial positioning system that has found many applications in geodesy and geophysics.

D oris missions: With more satellites carrying the Doris instrument, the system will make more accurate than before.