Based On The Subaperture Double-base Forward-looking Sar Imaging Algorithm

In the field of autonomous landing and disaster monitoring, the topography and objectives in front of the regional should be comprehended. Monostatic SAR (Synthetic Aperture Radar,SAR) cannot image the forward area due to the imaging principle. The isorange and isoDoppler lines could be approximately perpendicular in bistatic SAR mode owing to separated T/R platform, which makes forward-looking imaging possible. Through dividing data in azimuth, the subaperture algorithms realize real-time image in SAR system.Base on the subaperture imaging method, this paper focuses on the echo model, point target response function and algorithms, the main work s are shown as follows:1. The spatial coordinate model and echo model of bistatic forward-looking SAR are given; The range history properties and echo Doppler characteristics are analyzed The echo point target response of are studied, which provide the theoretical foundation for latter algorithm research.2. The performance of Matched Filtering and Dechirp methods are compared through simulation analysed; Advantages and limitations of the Dechirp method are presented, and based on this analysis, Step Transform Algorithm and OSA algorithm are studied.3. An imaging algorithm named Time-domain Subaperture Correlation Algorithm for bistatic forward-looking SAR is proposed. And the computational analysis is presented.4. Step Transform Algorithm for bistatic forward-looking SAR is proposed. By comparison with TDSC algorithm, the algorithm can process more efficiently, and realize fast and accurate imaging.