Digital Elevation Model

The Shuttle Radar Topography Mission (SRTM) was a project launched in 2000 to collect the most complete and up to date, contiguous high resolution topographic data, headed by NASA and the US DoD National Geospatial-Intelligence Agency (NGA).This sensor was launched on the space shuttle Endeavour and over eleven days collected measurements of elevation for almost one trillion points on the Earth’s surface. C-Band and X-Band Interferometric Aperture Radar was used to measure the elevation of the Earth between 60th parallel north and 56th south due to the orbital inclination, meaning the Baltic states are right on the northern limit of that range. After collection and processing, a global dataset was made freely available, at one arc-second (~30m) resolution for the US and three arc-second (~90m) for the rest of the world. As of 2015, NASA has began distributing the SRTM dataset for the rest of the world at the full one arc-second (~30m) resolution.
The SRTM dataset has various applications in areas where high detail topographic data is necessary such as agricultural management, flood risk analysis, civil aviation, mobile communications and military simulations. This particular image relies on the designation of grayscale pixel values to calculations of elevation and slope, which are conducted on the original numeric data. Finally the elevation data is used to offset the image to create the illusion of depth when seen through filtered spectacles. It forms part of a larger project proposing a new relationship between digital technologies of topographic measurement and the transformation of our traditional understanding of the construction of bounded polities.