一种调频连续波SAR的非线性距离多普勒算法

频率非线性是制约调频连续波雷达距离分辨率的一个关键因素。针对系统非线性误差对调频连续波(frequency modulated continuous wave, FMCW)合成孔径雷达（synthetic aperture radar, SAR）成像处理的影响以及雷达系统实时成像处理的需求，对存在频率非线性误差的调频连续波SAR回波信号进行了建模，分析了调频连续波去斜接收模式下的回波特性，深入研究了系统非线性误差校正的问题，提出了一种改进的调频连续波SAR的非线性距离〖CD*2〗多普勒成像处理算法。该算法通过非线性误差滤波器校正距离向非线性误差，具有计算量小，处理精度高的特点，适合实时成像处理。最后，通过理论推导和仿真分析，验证了算法的可行性和正确性。

Non-linear range-Doppler algorithm for FMCW SAR

The limiting factor to the range resolution of frequency modulated continuous wave (FMCW) synthetic aperture radar (SAR) is the well known presence of non linearities in the transmitted signal. The impact of non linearities in FMCW SAR is investigated, and the characteristics of beat signal are analyzed. Based on the model of FMCW SAR echo with non linearities, a proper improved range Doppler algorithm is proposed. This algorithm solves the non linearities problem for the whole range profile through one non linear filter. With the characters of low computation load and high processing precision, it is suitable for the de chirped FMCW SAR real time imaging. And the feasibility of the presented method is demonstrated by the simulation.