海杂波对ISAR成像的影响

针对逆合成孔径雷达(inverse synthetic aperture radar,ISAR)对舰船成像时实际回波中存在海杂波的现象,提出了不同参数下海杂波对ISAR成像影响的分析方法.在利用球不变随机过程(spherically invariant random process,SIRP)方法仿真出时空相关的二维K分布海杂波后,将其以一定信杂比(signal-to-clutter ratio,SCR)加入到目标回波信号中仿真出实际回波信号,利用图像熵和相关系数方法分析了海杂波形状参数的大小对ISAR像聚焦的影响;利用多普勒扩展方法分析了海杂波多普勒频移参数对ISAR多普勒频谱的影响;利用互相关法分析了不同SCR下海杂波空间相关对ISAR运动补偿的影响.仿真实验证明了分析结果的有效性.

Effects of sea clutter on ISAR imaging

Sea clutter exists in the realistic echo during the ship imaging with the inverse synthetic aperture radar(ISAR),this paper presents a method to analyze sea clutter effects on ISAR imaging with different parameters.Based on the spherically invariant random process(SIRP) method,two dimensional sea clutter temporally and spatially correlated coherent is simulated and combined with the synthetic target echo to generate realistic echo.Effects of sea clutter with different shape parameters on ISAR image focus are analyzed by using image entropy and correlation coefficient,effects of the Doppler frequency parameter of the sea clutter on the Doppler spectrum of ISAR are analyzed by using the Doppler spread techniques,and effects of the sea clutter with different signal-to-clutter ratio(SCR) on ISAR motion compensation algorithms are also analyzed by using cross correlation technique.Simulation results validate the analytic techniques.