SAR mapping technology and its application in difficulty terrain area

Abstract

In western China, there is a large area perennially covered by cloud, fog, ice, and snow. It is very difficult to acquire optical image for mapping in this area, so high resolution spaceborne synthetic aperture radar (SAR) images have to be used to make topographic maps. A scheme of SAR mapping technology is proposed in this paper. Digital elevation model (DEM) was extracted with stereo radargrammetry (StereoSAR), and topographic map was created with ideal SAR stereoscopic image pairs. Due to the difficult terrain, parallax edit under stereoscopic observation is used for improving matching result from stereo images. Ideal SAR stereoscopic image pairs generated with image simulation based on DEM are used for stereoscopic observation to extract topographic features. Ascending and descending image data were combined to solve the problem of lack of information caused by shadow and layover. Mapping experiment in western China shows that SAR data with resolution of 3–8 meters can be used to make topographic map at scale of 1∶50,000 by the scheme of SAR mapping introduced in this paper.