机动目标双基地ISAR越距离单元徙动校正算法

逆合成孔径雷达（Inverse syn thetic aperture radar, ISAR）使用距离多普勒算法成像时，当目标尺寸较大或转角过大 ，会发生越距离单元徙动（Migration through resolution cells, MTRC）现象，严重影 响 目标成像效果。基于双基地ISAR转台模型，针对成像的MTRC问题，对解线频调后的目标回波 进行研究，分析了机动目标MTRC的产生机理，并将匹配傅里叶变换（Match Fourier trans f orm, MFT）应用到MTRC的校正中，消除了快时间频率与慢时间的耦合项，有效解决了MTRC引 起的ISAR图像散焦问题。仿真结果表明，基于MFT的双基地ISAR MTRC校正算法能够有效校正 机动目标的距离徙动，提高ISAR成像质量。

Correction Algorithm of Migration Through Resolution Cells in Bistatic ISAR of Maneuvering Target

When the size of target is b ig or the rotation angle is big, migration through resolution cells (MTRC) may o ccur when employing range Doppler imaging algorithm in inverse synthetic apertu r e radar (ISAR), which can affect the imaging quality. Aiming at the problem of M TRC, the echo after dechirping is researched based on bistatic ISAR turntable mo del. And the cause of MTRC is analyzed. The match Fourier transform(MFT) is used to correct MTRC, which can eliminate the coupling of fast frequency, s low time and solve the image defocusing problem caused by MTRC. Simulation resul t shows that the correction algorithm based on MFT can correct the MTRC of maneu vering target and improve the image quality.