Research Progress of Global High Resolution Digital Elevation Models

There are many geologic processes that shape the surface of the Earth, and the evolution of topography provides us clues to the interior of the Earth and the forces that exist there. Firstly, in this paper, the origin and definition of digital elevation models (DEMs) are briefly introduced followed by their common acquisition methods according to ground-based, shipborne, airborne and spaceborne observation platforms. Secondly, the main characteristics of existing global high resolution DEMs are demonstrated with emphasis on nine commonly-used global DEMs. Thirdly, a common procedure for DEM quality evaluation is presented. Fourthly, the potential applications of DEMs to geological disaster monitoring and coastal vulnerability analysis are described. Taking the ongoing DEM projects in USGS (United States Geological Survey) and DLR (Deutsches Zentrum für Luft-und Raumfahrt) as examples, the requirements for high precision high resolution globally consistent and homogeneous DEMs and topobathemetric elevation models are discussed. Finally, the future trends and prospects of global high resolution DEMs are summarized. We find that fusion of multi-source remote sensing image data (such as LiDAR, SAR and optical remote sensing) has become an important approach to ge-nerate global multi-scale seamless DEMs, and the use of unmanned aircrafts and ships as observation platforms makes it possible to shorten the renewal cycle of high precision high resolution DEMs.