GEO spaceborne-airborne BiSAR resolution analysis and bandwidth and synthetic aperture time design

GEOSAR has the characteristics of wide coverage and short revisit time. But when the GEOSAR is both used as a transmitter and a receiver, its advantages is not well exploited. If an airplane or a LEO satellite is replaced as a platform of the receiver, we can not only observe the interesting regions flexibly, but also achieve finer resolution. However, the geometry of the BiSAR is complicated. Thus, it's not easy to acquire the resolution characteristics of an arbitrary BiSAR system. In this paper, starting with the resolution on the basic plane of a BiSAR system, and combining the resolution's projection relation between the basic plane and the plane tangent to the earth's surface, we obtain the resolution ellipse's expression on the ground. Finally, based on the expression, we optimize the two parameters including the signal bandwidth and the synthetic aperture time in order to realize the satisfactory resolution in a BiSAR system.