Design, navigation and control of relative motion for INSAR and BSAR formations

Synthetic Aperture Radar interferometric and bistatic techniques allow for a multiple exploitation of the transmitted signal, by means of two or more satellites flying in formation. To the purpose, the relative trajectory should be determined with a great accuracy and maintained close to a nominal one within a certain tolerance. In this paper the required formation's dynamics are accurately described and justified, according to the different remote sensing modes. In order to simplify the GNC architecture, a navigation system based on differential code GPS techniques, even if not reaching the accuracy of the carrier-phase approach, is demonstrated to provide the needed precision in the relative baseline estimation, therefore allowing the proposed control strategies to keep the formation in the desired configuration within the required tolerance.