Geosynchronous spaceborne-airborne bistatic SAR for earth observation: Advantages and main aspects

Geosynchronous synthetic aperture radar (GEO-SAR) offers new opportunities for continuous Earth observation missions with large coverage and short revisit cycle, which shows huge potential for bistatic observation. In this paper, the concept and advantages of GEO spaceborne-airborne bistatic SAR (GEO-BiSAR) are investigated. The system consists of a geosynchronous illuminator and an airborne receiver. Compared with a monostatic GEO-SAR system, the bistatic configuration can provide finer spatial resolution and higher signal-to-noise ration (SNR) with less system complexity. The influence of background ionosphere on GEO-BiSAR imaging is analyzed as well. Finally, the azimuth ambiguities of GEO-BiSAR signal caused by the limited transmitter PRF are described.