一种SAR图像舰船目标旁瓣去除方法

A Sidelobe Removal Method for Ship Targets in SAR Images

SAR图像舰船目标的几何结构参数对于SAR图像舰船目标识别具有重要意义,然而由于实际获取的SAR图像中舰船存在旁瓣干扰,导致提取的舰船几何结构参数和真实值相距甚远。本文提出一种基于距离约束的SAR图像舰船目标旁瓣去除方法,提出方法首先基于矩技术对目标方位角进行估计;然后利用获取的方位角将目标旋转至水平方向并提取目标主轴;最后通过比较舰船两侧到主轴的最大距离和平均距离对目标图像进行迭代,实现目标旁瓣去除。基于弹载和星载SAR图像舰船目标切片数据的实验结果表明,提出的方法能够有效去除旁瓣杂波,进而有利于获取精确的舰船几何结构特征。

The geometric structure parameters of ship targets in SAR images are of great significance for the recognition of such targets in SAR images.However,the extracted geometric structure parameters of ships are far from the real values because of the presence of ship sidelobe interference in the obtained SAR images.In this paper,a sidelobe removal method based on range constraint is proposed for ship targets in SAR images.Firstly,the azimuth angle of a ship target is estimated based on the moment technique.Then,the estimated azimuth angle is used to rotate the target to the horizontal direction and extract the target principal axis.Finally,the target image is iterated by comparing the maximum distance and average distance between two sides of the target and principal axis,removing sidelobe.A test is performed using slicing data of ship targets in spaceborne and missile-borne SAR images.The test results show that the proposed method can effectively remove sidelobe clutter,which is beneficial to obtain accurate ship geometric structure features.