This is a shaded-relief of the digital elevation model (DEM) extracted from the Lunar Reconnaissance Orbiter Camera (LROC) Narrow Angle Camera (NAC) stereo images from the Lunar Reconnaissance Orbiter mission. The original data product is a DEM from stereo images acquired at approximately 0.5 meters/pixel resolution, which allows an output DEM resolution of 1.5 to 2 meters/pixel using a softcopy photogrammetry system. However, in some cases, LROC DEMs were also generated at lower resolutions. The DEM was registered horizontally and vertically to LRO's Lunar Orbiter Laser Altimeter (LOLA) data.
The NASA Constellation Program (CxP) has identified 50 regions of interest on the Moon that the LROC NAC will image. A DEM is generated for each of these regions using the acquired NAC images. High resolution DEMs will be essential for identifying potential landing sites, landing site hazards, placement of landed assets on the surface, as well as other surface operations and navigation needs. Site-specific DEMs will also serve as a foundation for ortho-projection and control of local/site mosaics.
Hillshade processing was completed using Geospatial Data Abstraction Library (GDAL) tools on the original LROC NA DEM. To derive this shaded-relief one GDAL command was used: > > gdaldem hillshade input_dem output_hillshade -z 2 (ZFactor) -az 315 (Azimuth) -alt 45 (Altitude)> The shadows in the DEM were masked and images were used to fill in the shadowed areas where possible.
Shaded-relief, or hillshading, simulates shadows cast upon a raised topographic map, or more abstractly upon the planetary surface.