Research on the Extremum Points of Range-surface and Dopplersurface for Bistatic SAR

In the SAR system, some closed iso-range or iso-doppler contours in the area illuminated by the transmitter mean the ambiguity of some scattering points. In order to understand the closed properties of the iso-range or iso-doppler contours for bistatic SAR the paper studies the extremum points of range-surface and doppler-surface according to several mathematical models related to range and doppler. The formula for calculating the position of extremum point of range-surface has been given and several important conclusions about the stagnation or extremum points of doppler-surface have been drawn. Simulation results are provided and the theoretical analyses are validated.