双基地ISAR越距离单元徙动分析与校正方法

摘要

In bistatic inverse synthetic aperture radar (ISAR) system, range-dimension of the target image is defocused by migration through resolution cell (MTRC) of target scatter. In order to solve the problem, MTRC correction method is researched. Intermediate frequency direct sampling is used in the system. Matching filter pulse compression with non -coherent bistatic ISAR imaging mechanism is adopted and space target is taken as research object. The factor causing MTRC in bistatic ISAR is analyzed in detail when bistatic angle is constant during imaging process. Then the correction method based on Keystone transformation is put forward. And the correction method is validated by space target with ideal scatters.%空间目标双基地ISAR成像中,散射点的越距离单元徙动会造成目标像距离维的散焦,为解决此问题,研究了相应的越距离单元徙动校正方法.针对中频直接采样匹配滤波非相参双基地ISAR,以空间目标为研究对象,分析了成像期间双基地角固定不变时越距离单元徙动发生的原因,并以此为基础,借鉴单基地ISAR越距离单元徙动的校正思路,提出利用Keystone变换对目标像越距离单元徙动进行校正的方法,最后利用空间目标理想散射点模型对算法进行了仿真验证.