中轨SAR舰船动目标特性分析与定位技术

Characteristics Analysis and Positioning Technology of Ship Moving Targets for Medium Earth Orbit SAR

针对中轨合成孔径雷达(SAR)单通道模式下舰船动目标成像特性进行了分析。相比于低轨SAR,中轨SAR系统脉冲重复频率较低,舰船动目标成像极易发生模糊,且模糊像相距较远。在动目标定位处理中,为了获取动目标信号的完整方位包络以实现定位参数的准确估计,需要直接截取包含全部模糊像的切片图像,这会增加方位处理数据量,对于实时处理是一个巨大的挑战。因此,文中基于检测后的单模糊目标切片图像,提出了一种处理方法来完成动目标的精确定位。仿真实验表明,所提出的处理方法能够有效减少处理数据量,实现动目标的精确定位。

In this paper,the imaging characteristics of the ship-moving target in the medium earth orbit SAR single-channel mode is analyzed.Compared with low-earth-orbit SAR,the PRF of the medium earth orbit SAR system is lower,which implies the imaging of ship-moving targets is easy to be blurred,with the focusing position of blurred images being far apart.In the moving target positioning processing,to obtain the complete azimuth envelope of the moving target to achieve accurate estimation of the positioning parameters,it is necessary to directly intercept the slice image containing all the blurred images,which will increase the amount of azimuth processing data and is a huge challenge for real-time processing.Therefore,based on the detected single blurred target slice image,this paper proposes a processing method to complete the precise positioning of the moving target.Simulation experiments show that the proposed processing method can effectively reduce the amount of processing data and achieve precise positioning of the moving target.