使用ERS-1/2干涉测量SAR数据生成DEM

DEM Generation Using ERS-1/2 Interferometric SAR Data

干涉合成孔径雷达 (INSAR)数据已被证明能生产精确的数字高程模型 (DEM)。我们已开发了从单视 SAR复影像数据自动生成数字高程模型的新软件。基于 SAR多视强度影像的最小二乘影像匹配被用于复影像对的配准 ,达到很高的配准精度 (0 .0 1～ 0 .0 2像元精度 )。一种新的计算目标点 3维坐标 (X,Y,Z)的方程还被提出 ,卫星轨道、姿态和基线参数以及相位常数被纳入在方程中并被表示为时间的线性函数 ,利用至少 6个地面控制点能够同时估算这些参数。本文还给出了意大利埃特纳地区 ERS- 1 /2 SAR数据处理结果。

Accurate digital elevation model (DEM) can be produced by using interferometric SAR data. We have developed a new software on PC's that can automatically generate DEM from single look complex SAR pairs. The least squares image matching method based on SAR multi look intensity images has been used to register complex image pair. This method postulates a simple geometric relationship involving translation between two image windows to be matched, and then formulates a set of linear observation equations involving residuals. The optimal local translation is computed by minimizing the sum of the squares of these residuals. The typical accuracy of 0.01-0.02 pixel size can be obtained on multi look SAR images. We also present a new set of equations for calculating three dimensional coordinates at each pixel from unwrapped phases. The orbital position, attitude and baseline as well as phase constant have been involved in the equations. Using at least six ground control points, it is possible to refine interferometric baseline, and estimate phase constant, the orbit and attitude parameters simultaneously. Test results are provided for ERS 1/2 interferometric SAR scene pair acquired over Etna area in Italy during September 1995.