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Investigation of Velocities derived from Satellite Positions

Helmut Goiginger(1) and Roland Pail(1)

(1) Graz University of Technology, Steyrergasse 30, 8053 Graz, Austria


In the context of the analysis of the GOCE orbit data and the computation of the Earth's gravity field applying the energy integral approach, it is necessary to derive the velocities from the kinematic orbit positions of the satellite. Since the accuracy of the velocities is directly proportional to the accuracy of the satellite positions it is important to be aware of the behaviour of the differentiators. One of the main tasks is to investigate which differentiation method delivers appropriate ouput data. Furthermore the input parameter of several differentiation techniques play a key role in dependance on the resolution of the gravity field. In reality one always has to deal with noise on data which normally is not known until real data - in this case satellite positions - is available. Therefore, a noise has to be modelled and applied on the satellite positions to study the influence on the derived velocities. In this investigation two different numerical differentation strategies are compared and their impact on the gained gravity field model is analysed.


Workshop poster

Keywords: ESA European Space Agency - Agence spatiale europeenne, observation de la terre, earth observation, satellite remote sensing, teledetection, geophysique, altimetrie, radar, chimique atmospherique, geophysics, altimetry, radar, atmospheric chemistry