基于空间几何模型的星载SAR图像几何定位方法

Geolocating Method for Spaceborne SAR Image Based on Geometrical Model

星载SAR几何定位可以通过求解由三个约束条件组成的方程组来实现,但需要迭代运算。针对这一问题,将多普勒信息约束条件转化为卫星与目标之间的斜视几何关系,结合斜距方程和地球方程两个约束条件,建立了星载SAR空间几何模型。通过该模型实现了星载SAR图像像素的几何定位,并通过仿真数据对该方法进行了验证,同时对定位精度进行了仿真分析。

To avoid solving nonlinear equations with the iterative method in geolocating method for spaceborne SAR, the constraint condition from Doppler information was transformed to the squint geometrical relation between the satellite and target. The geometrical model of spaceborne SAR was established in company with the other two constraint conditions which were slant range equation and earth model. The locating of spaceborne SAR image was implemented based on this geometrical model. The effectiveness of this method was demonstrated and the locating precision was analyzed with simulated data.