Study On Key Techniques Of High-Dynamic Bistatic Forward-Looking SAR Imaging

Because the iso-range line and the iso-doppler line in the front area of its receiver could be approximately perpendicular, a bistatic synthetic aperture radar(BiSAR) can obtain images of the forward-looking terrain which is a blind imaging zone of a typical monostatic SAR system. Due to this great breakthrough, the signal processing methods for a bistatic forward-looking SAR(BFSAR)has become a hot topic in the remote sensing field recently. High-dynamic BFSAR is a new application of the BFSAR technology to the radar platforms with high dynamic and complex motions.Therefore, the high-dynamic BFSAR has significant application values in military areas for its capabilities of generating high resolution 2-D images to realize an auto target-seeking for the terminal guidance. Based on this background, this thesis mainly studies some key techniques for high-dynamic BFSAR imaging. The main contributions are as follows:(1) Analyzed the principle of high-dynamic BFSAR, discussed the characteristic of range history and doppler parameters. Moreover, derived the two-dimensional target spectrum based on the series reversion method.(2) Introduced three kinds of imaging algorithms of high-dynamic BFSAR under no motion error conditions, including linear Range-Doppler algorithm, polar format algorithm, generalized keystone transform algorithm, and the experimental results are given to demonstrate their effectiveness. At the same time, established the motion error model, analyzed it's influence on imaging detailedly.(3) Discussed the time-frequency synchronization error of high-dynamic BFSAR. Built time and frequency synchronization error models, analyzed their influence combined with simulation experiments.(4) Studied the imaging plane prediction methods and the target location method of high-dynamic BFSAR. First, analyzed the imaging plane detailedly, and put forward two imaging plane prediction methods: the geometric projection method and the range-doppler mapping method,which can obtain target view on imaging plane under given conditions. Then, presented a target location method based on the newton iteration method, it can calculate the position of targets accurately. Finally, the simulation results verified the effectiveness of the imaging plane prediction methods and the location method.