Accuracy Control of ASTER GDEM and Comparison to DSM Created with Classical Photogrammetric Techniques

ASTER Global Digital Elevation Model (GDEM) was released on June 29, 2009. The GDEM was created by stereo-correlating the 1.3 million scene ASTER VNIR archive, covering the Earth’s land surface between 83N and 83S latitudes. The GDEM is produced with 30 meter postings, and is formatted in 1 x 1 degree tiles as GeoTIFF files. Each GDEM file is accompanied by a Quality Assessment file, either giving the number of ASTER scenes used to calculate a pixel’s value, or indicating the source of external DEM data used to fill the ASTER voids.

In this study the accuracy of ASTER GDEM was examined using other DSMs created from ASTER stereopairs using classical photogrammetric techniques. Points of certified elevation collected with DGPS have been used to estimate the accuracy of the DSM. The elevation difference between the two DSMs was calculated. 2D RMSE, correlation and the percentile value were also computed and the results are presented