SRTM 3″ DEM (versions 1, 2, 3, 4) validation by means of extensive kinematic GPS measurements: a case study from North Greece

Abstract

In 2000, the Shuttle Radar Topography Mission (SRTM) provided for the first time a global high-quality digital elevation model (DEM) at resolution levels of one and three arcseconds, using single-pass synthetic aperture radar (SAR) interferometry. In January and February 2008, an extensive four-day kinematic global positioning system (GPS) (KGPS) campaign was carried out in the vicinity of the city of Thessaloniki (North Greece), during which more than 60 000 points were collected, providing an unprecedented density of measurements in the order of 20 points km⁻². The purpose of the present study was to assess the vertical accuracy of the four versions of SRTM 3″ DEMs that are currently available over the Internet for public use, on the basis of the KGPS data collected.

Acknowledgements

NASA, USGS and CGIAR–CSI are acknowledged for making this work possible by releasing the various versions of SRTM data to the scientific community. Dr Andy Jarvis (CIAT) is gratefully acknowledged for exchanging essential information on issues concerning SRTM versions and especially for providing an early copy of version 4. Special thanks to Ass. Professor C. Pikridas of the Faculty of Rural and Surveying Engineering, Aristotle University of Thessaloniki, for all the support related to the KGPS campaign and additionally, for all the corrections and important comments on this article. Professor K. Pitilakis and Dr Maria Manakou of the Civil Engineering Department, Aristotle University of Thessaloniki, are to be thanked for their altruistic support and for granting access to the EURO-SEISTEST establishment in Mygdonian Basin for the purposes of GPS data collection. The authors would also like to thank two anonymous referees, for significantly improving the final form of this article with their constructive comments and suggestions.