DEM Explorer: An online interoperable DEM data sharing and analysis system

Digital Elevation Model (DEM) data products are freely downloadable in tiled files from providers. But for most application needs, the area of interest does not exactly match the original spatial coverage of one DEM tile. After users obtain the files, they must mosaic, sub-set, and/or re-project them using geospatial software to generate the customized data that meet their requirements. It would be best if users could obtain the required DEM data directly. DEM Explorer is designed to share and explore the common DEM datasets in a publicly accessible online environment. It offers an intuitive and interoperable way to customize, download, visualize, and analyze DEM data in an Ajax-enabled Web interface. Via DEM Explorer, users are able to not only retrieve the original DEM files directly, but also obtain on-demand DEM data for any area of interest in a preferred format and projection. Deviations of terrain information are integrated as Web geoprocessing services in DEM Explorer to generate detailed terrain characteristics. DEM based hydrological models developed as Web services are aggregated to discover hydrological features. DEM Explorer has been adopted by the NASA Land Processes Distributed Active Archive Center to distribute the ASTER Global DEM to global users.