Accuracy assessment of ASTER and SRTM DEMs: A case study in Andean Patagonia

Abstract

The ASTER global digital elevation model (GDEM) and the SRTM-C digital elevation model (DEM) provide nearly global coverage, with spatial resolutions of 30 and 90 m, respectively. We assessed the geolocation, elevation, and morphological accuracy of the SRTM-C, the ASTER GDEM, and two single-scene DEMs derived from ASTER data for a site in Patagonia (ASTER DEMs). We found systematic and widely dispersed geolocation errors for the SRTM-C (Linear RMSE = 85.0 m) and the ASTER GDEM (Linear RMSE = 101.1 m). The SRTM-C had a narrow elevation error distribution (RMSE 8.3 ± 2.9 m), whereas the ASTER GDEM had a smaller RMSE (9.4 ± 2.3 m) than the analyzed ASTER DEMs. The ASTER DEMs provided more detailed morphological information than the SRTM-C, but also had more noise.