为进一步提高InSAR系统的DEM精度，分析非线性ECS自配准成像算法中4个影响相位保持精度的因素。研究结果如下：雷达和散射体之间的相对速度等效误差非常小，可以忽略；当系统分辨率优于0.1 m时，非线性自配准中的二次近似误差会引起超过0.1个像素的误差，要考虑其影响；非线性变标中的二阶泰勒近似误差非常小，可以忽略；成像时采用的平地假设误差，主要会引起干涉运动补偿的轨迹误差和相位补偿误差，对于高精度InSAR系统（高程精度优于0.5 m时），会造成一定的影响，要予以考虑。这些误差因素的分析，将为进一步优化提高InSAR成像处理中的相位保持精度及DEM精度提供一定的指导作用。
To further improve DEM precision for InSAR system,4 factors affecting phase precision are analyzed for the non-linear ECS auto-registration imaging algorithm.The results are given as follows.The equivalent error of relevant velocity between radar and scatter is very small and can be ignored.When the system resolution is better than 0.1 m,quadratic approximation error in the non-linear ECS auto-registration generates 0.1 pixel registration error,and it cannot be ignored.The second-order Taylor approximation error in the non-linear scaling is very small and can be neglected.During interferometric motion compensation,the flat assumption error in the imaging causes locus error and phase error,which cause some impact and should be considered for high-precision InSAR system (DEM precision is higher than 0.5 m).The above error analyes will provide some guidance for further improving phase maintenance precision and DEM precision.
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