Accuracy Assessment of ASTER GDEM in North Shaanxi

Abstract

For the preferred time-present, high accuracy and free availability, the ASTER GDEM becomes one of the most important global topographic data. Studies on accuracy assessment of ASTER GDEM are of great significance to its applications. However, the accuracy in specific area, like North Shaanxi province which is the main part of Loess Plateau of China, is not clarified ever before. In this paper, two main methods, namely root mean square error (RMSE) and contour matching difference (CMD), are used in accuracy assessment of ASTER GDEM. A RMSE map of ARSTER GDEM elevation in the North Shaanxi province is generated by comparing with the national DEMs with 1:10000 and 1:50000 map scales. The elevation error is higher in loess covered wind sand dune and Weihe river terrace area and is relatively lower in loess gully-hill area. However, the indicator of accumulate contour matching difference (ACMD) shows an inverse trend that most rugged area has a good contour matching result, compared with the bad contour matching result in the gentle relief area. In general the experiment indicates that the accuracy of Aster GDEM is similar to the national DEM with 1:50000 map scale, but greater with respect to topographic details.