一种同轨双基SAR的非线性CS成像算法

Focusing of highly-squinted bistatic SAR using the nonlinear CS algorithm for constant-offset configuration

针对大斜视情形下同轨双基合成孔径雷达(SAR)中目标的距离徙动和二次距离压缩(SRC)的空变性问题,基于严格解析的双基频谱,提出了一种适用于同轨双基SAR的非线性线频调变标成像算法.与适用于小斜视角条件的线频调变标成像算法不同,该算法不仅考虑了调频率随多普勒频率的变化,而且也考虑了其随距离的线性变化,更好地实现了同轨双基SAR中SRC的精确补偿,取得了满意的聚焦效果.仿真实验验证了所提算法的有效性.

Focusing on the range variance of the range cell migration （ RCM ） and the second range compression （ SRC） for tandem bistatic SAR with high squinted angles , a nonlinear chirp scaling algorithm （ NCSA） is proposed to handle the problems based on an exact analytical bistatic spectrum . Unlike the chirp scaling （ CS） imaging algorithm which is suitable for the case with small squint angles , not only is the variation with the Doppler frequency considered for the Doppler chirp rate , but also its variation with range is taken into account . The proposed algorithm can compensate the SRC for tandem bistatic SAR well . Satisfactory results are obtained with simulated experiments .