Analysis of Diving Configuration Of Bistatic Forward-Looking SAR Based on Nonlinear Chirp Scaling Algorithm

Monosatic SAR can not image targets in forward direction due to the overlapping of the 2-D resolution directions. Then bistatic forward-looking SAR can aquire high resolution 2-D image in forward direction by placing transmitter and receiver on different platforms. The diving configuration of bistatic forward-looking SAR that the transmitter flies in a straight line and the receiver dive down can be realized for one of the bistatic platforms. Compared to the traditional airborne bistatic SAR, the receiver diving configuration has a more severe 2-D coupling, so imaging processing is more difficult. This paper analyzes the 2-D resolution of the special configuration, also range and doppler formula are determined based on the gradient theory, which are used to determine parameters that affect imaging ability. The accurate form of signal spectrum is obtained by the method of series reversion. Besides, an improve NCS algorithm is used to simulated and real bistatic data acquired from bistatic forward-looking SAR experiment. The results show the success of the experiment and the feasibility of the algorithm.