WP2: Radioscience (Research and technological development)


The objective of the WP2 is to provide biases residuals of spacecraft tracking data analysis with respect to a given ephemerides.

Description of work

Task 2.1: Collection of the radioscience tracking data

Radioscience data will be collected from spacecraft which have flyby of satellites. These data are available on the PDS data basis. They will be downloaded; their format will be understood; and they will be transformed into a format that the ROB software can use. These datad will also be re-written in a more suitable 'standard' format for the use for a larger community.

Task 2.2:Collection of a priori ephemerides

A priori ephemerides of the planets and their satellites (including in particular their mass) will be collected and implemented in the ROB software.

Task 2.3: Strategy development for the analysis (in terms of arc length and spacecraft non-gravitational forces)

Simulations will be performed for identifying the best strategy to obtain the ephemerides biases. These simulations will be adapted to each satellite/moon. The possible non-gravitational forces acting on the spacecraft will have to be corrected for.

Task 2.4: Analysis of the tracking data

The data will be analysed with software available at ROB: the GINS software. This software allows to process tracking data in order to obtain the gravitational forces induced by the moon, the non-gravitational forces acting on the spacecraft, and the ephemerides biases. In this process, precise orbit to the spacecraft will be computed.

Task 2.5: Optimization of the strategy and analysis for obtaining ephemerides biases

The length of the observation arc will have to be accepted to each spacecraft and iterations with different strategies will have to be performed in order to obtain the best ephemerides biases as possible.