Two radar satellites flying in close formation are to begin generating a three-dimensional map of the Earth’s entire surface, with terrain heights accurate to within two metres.

The €165 million TanDEM-X satellite launched on 21 June (press release); it will electronically combine its antenna with the nearly-identical TerraSAR-X, which launched in June 2007, to produce a stereoscopic portrait of the globe by 2013.

The satellites, which will fly at minimum 200 metres apart and use microwave (X-band) radar, are both public-private partnerships between the German Aerospace Center (DLR) and the space company EADS Astrium.

“Our aim is to generate a model at a resolution and a quality that doesn’t exist today,” the BBC quotes Dr Vark Helfritz, from Infoterra – the subsidiary of EADS Astrium which is marketing the data to commercial buyers.

Nature’s Quirin Schiermeier has all the details on radar satellites such as TerraSAR-X – and their commercial promise – in a 2007 feature, Radar satellites: mountains to molehills.

Image: DLR