星地双基地SAR观测模式与成像处理研究OA

Space-surface bistatic synthetic aperture radar(SS-BSAR)takes in-orbit satellites as non-cooperative illuminators,offering advantages such as high timeliness,multi-dimensional information acquisition,and multi-frequency fusion.However,its bistatic geometry introduces pronounced spatial variation in its imaging performance,and the observation modes affect the key system metrics like resolution and signal-to-noise ratio(SNR).In view of these,the multi-observation modes and imaging processing of SS-BSAR are investigated.First,the operating principles and characteristics of the stripmap mode and terrain observation by progressive scans(TOPS)mode are compared and analyzed.Then,the two-dimensional resolution and SNR performances of the SS-BSAR system are analyzed.Finally,the imaging performance analysis and point-target simulations are conducted with the parameters from the LT-1(stripmap mode)and Sentinel-1(TOPS mode)satellites by a processing method suited to non-cooperative SS-BSAR.The results show that the SS-BSAR imaging performance exhibits spatial variability across the scene,with the TOPS mode suffering significantly lower azimuth resolution and coherent integration gain than the stripmap mode due to beam scanning.