ASTER GDEM V2的南极冰川高程误差校正及精度分析

ASTER GDEM V2 is one of the most widely used DEM data for Antarctic Ice Sheet analysis. However, it cannot be directly used due to its large anomalies in the snow-covered plateaus of the continent, where the surface reflectance is very high and no obvious surface features are available for the generation of high-quality DEM. This study rectifies the large anomalies in ASTER GDEM V2 over Byrd Glacier using a contour correction method. Then the accuracy of the anomaly-corrected ASTER GDEM V2 is quantitatively evaluated against. Results show that the RMSE of ASTER GDEM V2 decreases from 26.56 m to 18.77 m (-6.79 m), which is lower than the RMSE of ICESat-1 DEM (121.24 m). In addition, the accuracy of the corrected ASTER GDEM V2 is barely influenced by slope and no significant systematic errors can be observed. In contrast, the accuracy of ICESat-1 DEM is very sensitive to slope. Through further topographic profile analysis, the noises on previously non-corrected ASTER GDEM V2 are found to be mainly distributed in the low flat areas. Those noises can be effectively removed by using the contour correction method. This study indicates that the corrected ASTER GDEM V2 is well qualified for analyzing Byrd Glacier, Antarctica.