MTPT 方法估计机载SAR 残余运动的两个影响因素

由于导航系统测量精度的限制，载机的位置经常存在厘米级的误差，该误差称为残余运动误差。对于机载超高分辨SAR 系统或机载重轨干涉SAR，必须估计并补偿该残余运动误差。MTPT 方法可以估计单幅SAR 图像中的残余运动误差，但是速度和斜距的误差会影响该方法的精度。该文在详细分析速度和斜距误差对MTPT 方法进行残余运动估计的影响的基础上，利用仿真和实测SAR 数据验证了这一点。同时还指出，MTPT 方法虽然可以估计速度和斜距误差，但是它们的精度敏感于相位测量误差；在利用MTPT 方法进行估计之前必须先利用其它更为准确的方法消除平台的速度误差和目标的斜距误差。 

Two Factors Influencing Residual Motion Estimation in Airborne SAR Images with MTPT

motion errors, frequently occur in SAR images. For airborne SAR system with very high resolution and airborne repeat-pass SAR interferometry, the residual motion errors must be estimated and compensated. Multi-squint Technique with Point Targets (MTPT) is able to estimate the residual motion errors for an individual SAR image, but errors in the platform velocity and the slant range will deteriorate the accuracy of the method. Based on the detailed analysis of the velocity and slant range to residual motion error estimation, simulated and real SAR data are used to validate it in this paper. It is also pointed out that though MTPT is able to estimate the errors in the velocity and slant range, it is sensitive to the phase error. Therefore, it is advised that the errors in the velocity and slant range should be removed with other precise method before MTPT is utilized to estimate the residual motion errors.