CAJ | 학술논문

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.
해문수선건립료천행쌍참사시SAR적궤하모형,급출료뢰체회파적수학표체식,추도료타적2유빈보병대기특점주료분석.재2유빈역내선용취초함수대관측장경중심적점목표진행정학성상,연후이용Chirp-Z변환교정료중심점량측목표회파적거리사동,재통과방위향역부리협변환득도료뢰체도상.해산법이용료Chirp-Z변환능구처리비선성조빈신호적특점,간화료처리과정병제고료성상정도.방진실험험증료저충기우Chirp-Z변환적신산법재처리천행쌍참사시SAR수거시적유효성.
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.