星载SAR的空中运动目标检测和成像

根据星载SAR(Synthetic Aperture Radar)通常信号带宽较大的特点,本文提出了一种子带双频共轭处理方法,降低合成信号的等效中心频率,去除多普勒模糊,进而利用Keystone变换完成低信噪比高速运动目标的距离走动校正.运动目标的距离弯曲校正后,采用时频分析实现目标的低分辨率成像和检测.利用检测过程中获得的目标径向速度,进一步完成了各个运动目标的高分辨率成像处理.仿真结果表明了本文方法的有效性.

Spaceborne SAR Detecting and Imaging of Airborne Moving Targets

According to the characteristic that the bandwidth of spaceborne SAR(Synthetic Aperture Radar) is generally quite wide,a method called "Sub-band Double Carrier Frequency Conjugated Processing" is presented.The approach can decrease the equivalent central frequency of the synthetic signal and remove the Doppler ambiguity.Consequently,Keystone transform can be used to correct the linear range migration of the fast moving target with low input SNR.After the target range curvature is corrected,time-frequency analysis can be used to implement low resolution imaging and targets detecting.The radial velocities of targets can be obtained from targets detection,and high resolution imaging process can be completed to each moving target.The simulation results show the effectiveness of the new method.