Construction of a high-resolution DEM of an Arctic ice cap using shape-from-shading

Digital elevation models (DEMs) of ice sheets and ice caps are usually cons tructed from elevation data acquired from airborne or satellite-borne altim etric systems. Consequently, the DEMs have a spatial resolution of about 1 km which limits their use for most glaciological and remote sensing studies . In this paper we investigated the possibility of using a shape-from-shadi ng technique, applied to a Landsat MSS image, to create a high spatial reso lution DEM of Austfonna, an ice cap in Svalbard. A high correlation (coeffi cient of determination = 0.85) was observed between Landsat pixel brightnes s values, acquired during winter, and the surface slope component parallel to the solar azimuth. This relationship was used to create a DEM by calcula ting surface elevation profiles across the ice cap, using low spatial resol ution radio echo sounding data as tie points. The resulting DEM had an esti mated rms error of about 14 m, with the error occurring mostly at low spati al frequencies. Shape-from-shading produces less accurate DEMs than interfe rometric SAR (InSAR) techniques. Nevertheless, in scenarios for which InSAR cannot be used to construct a DEM, shape-from-shading provides an acceptab le alternative.