一种逆合成孔径激光雷达成像算法

Imaging algorithm for inverse synthetic aperture LIDAR

逆合成孔径激光雷达是一种能实现对运动目标超高分辨实时成像的主动式有源成像雷达。该雷达系统发射的激光信号具有超高频率和超大带宽的特点,因此,微波波段逆合成孔径雷达针对常规目标所采用的回波信号模型不再适用。针对这一问题,给出了适用于逆合成孔径激光雷达的运动目标回波信号模型,分析了激光信号的超高频率带来的脉内多普勒效应,利用基于参考点的运动补偿方法,在匹配滤波处理后通过包络对齐实现对运动参考点轨迹的精确估计,最终获得了精确的参考信号,实现了对运动目标的超高分辨二维成像。仿真结果验证了该算法的有效性。

Inverse synthetic aperture LIDAR is an active imaging system,which can achieve high resolution instantaneous imaging for moving targets.Due to the ultra-high frequency and ultra-wide bandwidth of the laser signal,the normal echo signal model used in the microwave inverse synthetic aperture radar is not fit for the inverse synthetic aperture LIDAR.In order to solve this problem,the echo model for the inverse synthetic aperture LIDAR is presented and the intra-pulse Doppler effect induced by the laser signal is analyzed.By using motion compensation method based on the referrence point,the accurate estimation of reference point′s track is obtained after matched filtering and envelop alignment.At last,2-D image of the target with super-resolution is obtained and the simulation results validates the effectiveness of the imaging algorithm.