A special kind of anniversary took place on 20 June, some 14,000 kilometres south of Germany in the Antarctic. There, at DFD’s German Antarctic Receiving Station GARS O’Higgins, the DFD crew celebrated the 50,000st TerraSAR-X orbit.
The German radar satellite TerraSAR-X was launched in 2007 and since 2010 has flown together with its twin, TanDEM-X, in a never before realized double helix orbit. This enables the satellites to jointly record the earth’s entire surface repeatedly “in stereo”. With this data, EOC produced the world’s most precise terrain model of the earth with 12 metre horizontal resolution and relative height accuracy better than two metres.
DLR’s two polar stations at O’Higgins in the Antarctic and Inuvik in Canada’s high north are essential components of these satellite missions. Only at such extreme locations are polar-orbiting satellites visible during every orbit. This means that the satellites’ storage unit can be emptied at least twice per orbit, freeing it to acquire new data and considerably increasing the reception capacity of the missions. In 50,000 overflights countless terabytes of data were acquired, stored on tape, and sent to Europe. In addition, the data covering the Antarctic are processed in near real time in order to monitor ocean ice cover or icebergs in the region. For this purpose the measurements are assessed directly at the station in an automated routine process without the involvement of the crew. Instead of a massive amount of raw data, only the relevant processed results can be sent by email, for example to the bridge of a research vessel.
Nevertheless, despite many automated processes there is still lots to do at the DLR station, which will be 25 years old this year.
The “Jubilee Orbit” is thus a welcome change for our colleagues, who are on the job 24/7 at the station in polar winter.