MERIT DEM now available for download in MRR format
The MERIT DEM is a global scale terrain DEM at 3 arcsecond resolution with coverage from 60 degrees South to 90 degrees North. So, it excludes Antarctica but includes the Northern Latitudes, which is a considerable improvement over similar DEM’s derived from Shuttle Radar Topography Mission (SRTM) data. It was developed by Dai Yamazaki at the University of Tokyo.
The MERIT DEM is based on NASA SRTM3, JAXA AW3D-30m and Viewfinder Panoramas’ DEM data, but also draws upon supplementary data to provide improvements and corrections. Although the 3 arcsecond resolution is not high (approximately 90 meters), in my opinion it is a very high-quality DEM suitable for medium and large-scale applications.
The DEM is now available in MRR format and can be downloaded from the MERIT DEM website. The file is 47.1 GB including all overview resolution levels. The MRR was created by merging the MERIT DEM tiles into a single raster. No modifications were made, except to restrict the vertical resolution of the data to 0.01 meters and to round all elevation values to the nearest centimeter. The original data uses unrestricted 4-byte floating-point resolution. By restricting the vertical resolution to a reasonable level, the MRR can compress the raster more efficiently and reduce the total file size. MRR format rasters can be displayed in the MapInfo Pro GIS platform. This is a commercial application, but you can acquire a free viewer subscription which will display rasters in MRR format. You can also display MRR format rasters in QGIS or any other application that uses the GDAL raster library. You can download a GDAL driver for MRR from the Precisely support website.
On the MERIT DEM website, you can find all the terms and conditions for the user of this raster. These terms have been duplicated in the MRR raster metadata property, which you can view in MapInfo Pro Advanced via the Raster Info dialog. Please make sure you adhere to the licensing restrictions when you use this raster!