SPACE STATION BASED TETHERED INTERFEROMETER FOR NATURAL DISASTER MONITORING

A synthetic aperture radar interferometer based on two vertically spac ed physical antennas carried along parallel paths by the Space Station and by a small tethered subsatellite is presented. This remote sensin g system is aimed at producing and updating topographic maps. In parti cular, it offers geometric, radiometric, and temporal resolutions adeq uate for natural-disaster monitoring. The system performance is identi fied by means of a computer simulation, taking account of the tethered platform dynamics and of the Space Station orbital decay. Numerical r esults show the capability of observing any point of the Earth surface in the range of latitudes +/-51.6 deg with a repetitivity of about 2 days, by using range steering of the antenna beams (15-45 deg). Then, the attitude pointing accuracy requirements are derived by evaluating the signal-to-noise ratio and the swath overlap decrease due to the an tenna misalignment (yaw 0.15 deg, pitch 0.10 deg, roll 0.20 deg).