ANALYSIS OF ORBIT PROPAGATION AND RELATIVE POSITION ACCURACY OF SMALL SATELLITES FOR SAR INTERFEROMETRY.

Abstract

The accuracy of the orbit prediction has a remarkable impact on the operations of satel-lites: orbit maintenance, maneuver planning, data-take and data-download scheduling, etc. Especially for SAR-Interferometry missions the requirements to the prediction accuracy are enormous. Within this paper a new method will be presented to rise the prediction accuracy of commercial available orbit propagation tools. Combining the non-gravitational forces affecting the spacecraft, measured by mean of an accelerometer, an optimal modified drag coefficient can be calculated and implemented in the orbit propagation tool. The accuracy which can be reached with the presented method, after a propagation of 3 days, is about 10÷15 m RMS in cross-track and radial direction and about 100 m RMS in along-track direction.