Digital elevation model generation and accuracy assessment using aster satellite image

Abstract

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is on-board the National Aeronautics and Space Administration?s (NASA?s) Terra spacecraft that provides along-track digital stereo image data at 15m resolution. The ASTER digital stereo image could be used to generate digital elevation model (DEM) that represents the terrain elevation in discrete form in three-dimensional (3D). This is the simplest form of 3D-terrain representation. In this study, DEM was generated from ASTER stereo image covering south of Malaysia and part of Singapore. The results were carried out using PCI Geomatica and ENVI softwares. The accuracy of generated DEM is highly depending on the number and accuracy of collected ground control points. The DEMs were generated using 25 ground control points. Also in this study, a high accuracy DEM was used as a base or reference value for accuracy assessment of the generated DEMs. For this purpose, the height of five (5) check points from the generated DEMs were used to compare them with the corresponding point of the high accuracy DEM to determine the accuracy of the generated DEMs. Results indicated that root mean square error (RMSE) is about ±4 meters. According to the image resolution of 15 m and selected number of check points (5), the result is acceptable and it could be used for various applications.