Terrain elevations from InSAR incorporating ground control data

Interferometric SAR (InSAR) techniques permit the production of elevation maps of an area through interpretation of interference fringes between two SAR images of the same region. However, uncertainty in orbit determination causes an absolute height error of the order of several hundred meters. It is a systematic error which affects every point in the image, but can be removed using known heights of a few control points in a given image scene. A model is developed to calculate absolute terrain elevation incorporating ground control points. The computation procedure is based on stereo radargrammetric mapping of overlapping SAR images, incorporating expressions for elevation based on the fringe information. The model uses second order polynomials for orbital position and first order polynomials for satellite velocity