A new algorithm for interferometric DEM geocoding

SAR Interferometry can be used to derive topographic information (DEM) on the earth surface. An operation called geocoding is necessary to translate the DEM from a range-azimuth to a latitude-longitude reference system. This paper introduces a new algorithm for geocoding interferometric DEMs based on an iterative procedure using the reference ellipsoid as the first guess, then locating each earth point on a succession of planes locally parallel to the ellipsoid. The procedure is shown to geometrically converge to the considered DEM point. Given its high accuracy, this method could be used as a precision tool for use in difficult zones.