基于Chirp-Z变换的串行双站斜视SAR成像算法

该文首先建立了串行双站斜视SAR的几何模型，给出了雷达回波的数学表达式，推导了它的2维频谱并对其特点做了分析。在2维频域内先用聚焦函数对观测场景中心的点目标进行精确成像，然后利用Chirp-Z变换校正了中心点两侧目标回波的距离徙动，再通过方位向逆傅里叶变换得到了雷达图像。该算法利用了Chirp-Z变换能够处理非线性调频信号的特点，简化了处理过程并提高了成像精度。仿真实验验证了这种基于Chirp-Z变换的新算法在处理串行双站斜视SAR数据时的有效性。

Tandem Bistatic Squint SAR Imaging Algorithm Based on the Chirp-Z Transform

This paper firstly setups the geometric model of the tandem bistatic squint SAR and presents the mathematic expression of the radar echoes, then its two-dimensional frequency spectrum is derived and its characteristic is analyzed. In two-dimensional frequency domain, the point targets in the center of the observed scene is precisely imaged by using the focusing function, then the Chirp-Z transform is used to correct the range cell migration of the target echoes in both side of the center points. Finally, the radar images are obtained by the inverse Fourier transform on the azimuth direction. Since the algorithm uses the property of the Chirp-Z transform processing the nonlinear modulation frequency signal, the processing procedure is simplified and the imaging precision is greatly improved. The simulation tests validate this new algorithm based on the Chirp-Z transform to process the data of the tandem bistatic squint SAR.