Doppler Properties of Spaceborne/Airborne Hybrid Bistatic Synthetic Aperture Radar

In this paper, a special geometry case of spaceborne-airborne bistatic SAR (SA-BiSAR) is considered, in which satellite and aircraft flight paths are parallel and their antennas are steering at the strip map. This case is a simple but typical application example, which is applicable for non-cooperative illumination. The integration time of SA-BiSAR system is derived via the motion of transmitter and receiver footprint. In parallel and stripmap mode, Doppler frequency is obtained through the combination between spaceborne and airborne SAR. Other Doppler properties have been envisaged, including Doppler bandwidth and azimuth resolution. The overall simulation experiments are conducted and some characteristics are exhibited. The critical parameters, which have the significant effect on the SA-BiSAR Doppler properties, are extracted by analytical expressions and numerical simulations. In parallel and strip map mode and with reference to ENVISAT-1, SA-BiSAR system possesses the potential of yielding 10 m azimuth resolution and 0.5 s integration time for C-band via the analysis of simulation results.