DORIS (geodesy)

Doppler Orbitography and Radio Positioning Integrated by Satellite, DORIS short, is a system of satellite geodesy, which comprises about 50 dedicated ground stations. It serves for the precise determination of the orbit of satellite orbits using the Doppler effect of radio signals. The global distribution of satellite stations, the method also contributes to the modern global reference systems of geosciences at ( see GNSS / GPS and IGGOS ) and ongoing monitoring (monitoring) of the Earth's rotation.

DORIS is a further development of the principle previously used by the transit of satellite Doppler satellite. However, it reverses the process by which high-precision radio signals are not emitted by the satellites, but the ground stations on two frequencies. In orbit, the signals are registered by special units of measurement, however, the technically complex data analysis takes place on the earth's surface. The use of two frequencies increases it (similar to GPS) measurement accuracy.

The system was developed around 1990 in France and in the satellite requires only relatively little effort, while the ground stations are integrated into a complex telemetry and survey network. It achieved accuracies in the decimeter range, making other methods such as GNSS or Satellite Laser Ranging somewhat inferior, but has the advantage of global evenly distributed measurement data. Therefore, it is part of the international IUGG services and recognized as part of the ITRF system.

The units of measurement can be divided into different types of satellite install and include integrated as accessories in the Envisat, Cryosat -2 and some Altimetriesatelliten like Jason. Regional and time-based measurement campaigns DORIS can beistellen the global frame of reference.