ASTER DTM vs GTOPO30 and 1/250.000 topographic maps - The case of Lefkas Island, Greece

In this paper, we present the use of ASTER data for the creation of a Digital Terrain Model (DMT) of high accuracy. The area of study is Lefkas Island in the Ionian Sea. For the creation of the DTM, we used an ASTER stereo-pair dating January 01, 2001. The images cover an area of 60times60 km The images have been received in the near infrared (0.78-0.86 mum) part of the spectrum with a spatial resolution of 15 m. We created a 15 m-pixel size DTM. Then, we compared that DTM with the following DTM´s a) A GTOPO30 DTM b) A DTM created from digitized contours of 1/250.000 scale topographic maps. We first made an optical comparison of the DTMs. Then we subtracted the DTM created from ASTER data from the DTM created from digitized contours and we presented their difference. Finally, we verified the DTMs accuracy using different points of well-known elevation. All the results demonstrated that DTMs derived from ASTER data have very good accuracy that depends on the accuracy of the ground control points and could be ranged between 15-25 meters