Radar Imaging From Geosynchronous Orbit: Temporal Decorrelation Aspects

Synthetic aperture radar imaging from geosynchronous orbit has significant potential advantages over conventional low-Earth orbit radars, but it also has challenges to overcome. The baseline mission we consider is an L-band geosynchronous passive (bistatic) radar achieving a spatial resolution of about 100 m with an integration time of 8 h. The atmosphere changes its structure on timescales of minutes to hours, and this has to be compensated if useful images are to be provided. The analysis shows that ionospheric delay is the major source of temporal decorrelation; other effects, such as tropospheric delay and Earth tides, have to be dealt with but appear to be easier to handle.