Tandem-X, the partner satellite of the German TerraSAR satellite, was successfully launched today. It will now fly in formation with Terrasar, another synthetic aperture radar (SAR) satellite, and collect data from which a detailed elevation model of the earth surface will be generated. Uniquely this system will be based on SAR interferometry techniques and is therefore not hindered by cloud or surface texture factors.
The end goal is a global, detailed and accurate elevation model free of the anomalies present in current datasets such as G-DEM. It also promises to be more detailed with pixel spacing of 12 metres. For comparison see the graphic below and consider that SRTM provides data at 90m resolution and G-DEM at 30m. Of course in polar regions we will suffer from the usual data gap at extreme latitudes, but an orbit inclination of ~98 degrees means coverage for almost all steep terrain in the Antarctic, only missing parts of the Trans Antarctic Mountains.
The global elevation data is expected to be available in 2013 and will be distributed by Infoterra, but more news here if any coverage is available before that date. No details on data licence and costs yet.