匀速运动目标逆合成孔径激光雷达成像算法  

Inverse synthetic aperture ladar imaging algorithm for uniform motion targets

作　　者：阮航[1,2] 吴彦鸿 叶伟 

机构地区：[1]装备学院光电装备系,北京101416 [2]北京跟踪与通信技术研究所,北京100094 [3]装备学院信息装备系,北京101416

出　　处：《红外与激光工程》2014年第4期1124-1129,共6页Infrared and Laser Engineering

基　　金：国家863计划

摘　　要：由于逆合成孔径激光雷达(ISAL)发射信号具有超短波长、超大带宽的特点,在对匀速运动目标成像时,其回波信号存在色散效应,且目标散射点容易产生越距离单元徙动,利用传统的距离-多普勒成像算法将无法获取理想的ISAL图像。在对匀速运动目标回波精确建模的基础上,深入分析了由于目标运动引入的距离色散。提出利用分数阶Fourier变换(FRFT)补偿距离像色散,并对距离压缩后的回波信号进行预相干化处理,之后结合keystone变换消除目标散射点存在的越距离单元徙动,并最终实现对目标的高分辨成像。仿真实验验证了成像算法的有效性。The transmitting signal of inverse synthetic aperture Ladar （ISAL） has the characteristics of short wavelength and large bandwidth. When imaging an uniform motion target, dispersion in range direction and migration through resolution cells （MTRC） exist in the ISAL image. Therefore, the conventional range-Doppler imaging algorithm is inapplicable. The precise ISAL echo model was established for an uniform motion target, and the motion-induced range dispersion effect was analyzed in detail. In this paper, an ISAL imaging algorithm was proposed for uniform motion targets. The fractional Fourier transform（FRFT） was adopted to eliminate the range dispersion. By using the keystone formatting technique, the MTRC was compensated after a pre-coherent processing to the range-compressed signal. Finally, the high-resolution ISAL image was realized. Simulation results confirm the validity of the proposed imaging algorithm.

关 键 词：逆合成孔径激光雷达 匀速运动目标 分数阶FOURIER变换 越距离单元徙动 inverse synthetic APERTURE ladar(ISAL) FRACTIONAL FOURIER transform(FRFT) migration through resolution cells(MTRC) 

分 类 号：TN958[电子电信—信号与信息处理]