Bistatic synthetic aperture radar with non-cooperative LEOS based transmitter

The authors consider Low Earth Orbited Satellite (LEOS) systems for personal communications. Their rather high power spectral density near the Earth surface could be used for aircraft detection. Bistatic radars that utilize communication signal transmitting from LEOS could operate in a passive mode. Moreover, the targets will be characterized by their bistatic radar cross-section (RCS) that could be 20 to 40 dB larger than the monostatic RCS. Another LEOS peculiarity is their high speed relative to the surface. This fact can be used for radar applications, namely: to design a bistatic synthetic aperture radar (SAR). Such a bistatic radar has a receiving subsystem near the acquisition scene (restricted usually by the horizon line) and the transmitter is the satellite transmitting communication signals. The direct communication line could be used for the heterodyne synchronization. It is important to mention, that a heterodyne signal should be formed that way in order to avoid or maximally reduce the Doppler frequency shift in the heterodyne circuit. In the present paper, using a particular example, the authors demonstrate the feasibility of this approach and evaluate parameters for system development. The example system demonstrates the feasibility of vessel detection at sea.