一种适用于合成孔径激光雷达宽场景成像的频域变标算法  

Frequency Scaling Algorithm for Synthetic Aperture Ladar Imaging with Wide-Scene

作　　者：李小珍[1] 吴玉峰[2] 郭亮[1] 曾晓东[1] 

机构地区：[1]西安电子科技大学技术物理学院,陕西西安710071 [2]西安电子科技大学雷达信号处理国家重点实验室,陕西西安710071

出　　处：《光学学报》2013年第12期303-310,共8页Acta Optica Sinica

基　　金：国家自然科学基金(61107006);中央高校基本科研业务费(K5051305005)

摘　　要：合成孔径激光雷达(SAL)由于信号波长短,造成波束光斑脚印较小,限制了成像场景的幅宽。针对该问题,将合成孔径雷达(SAR)中常用的宽场景测绘TOPS模式推广应用到SAL中,并针对SAL的信号特性,提出了一种可行的成像算法:采用基于谱分析的方位预滤波方法,消除由于波束转动导致的方位信号模糊,获得信号无模糊的二维频谱;利用改进的频率变标算法(FSA)完成距离压缩及距离徙动校正,并校正平台连续运动引入的多普勒频移;结合去斜技术将信号聚焦在方位频域,获得无模糊的SAL图像。仿真结果验证了该算法的有效性。Due to the short wavelength of the signal in synthetic aperture ladar （SAL）, the spot size is very small, which limits the imaging field. For this problem, the common wide-scene imaging mode in synthetic aperture radar （SAR）, i.e., the TOPS imaging mode, is extended and applied in SAL, and according to the signal characteristic of SAL, a suitable imaging algorithm is proposed. The azimuth pre-filtering based on the spectrum analysis is adopted to eliminate the aliasing caused by the steering of the antenna beam and the signal spectrum without alias is obtained. The improved frequency scaling algorithm （FSA） is used to complete the range compression and range cell migration correction. Also, the Doppler frequency shift induced by the continuous movement of the platform is compensated. With the dechirp technique, the signal is focused in the Doppler domain and the SAL image without blurring is obtained. Simulation results are provided to demonstrate the effectiveness of the proposed method.

关 键 词：遥感 激光雷达 合成孔径 宽场景成像 频率变标算法 方位预滤波 

分 类 号：TN958[电子电信—信号与信息处理]