Airbus Defence and Space

TanDEM-X radar satellite sends first images in record time

TanDEM-X has already beaten its “twin” TerraSAR-X by returning its first images last Thursday – just three days and 14 hours after its launch on 21 June. The first images, received and processed at the DLR (German Aerospace Centre) ground station in Neustrelitz, show the North of Madagascar, a landscape in the Ukraine and the city of Moscow.

Wave movement clearly visible around Madagascar

The above right acquisition depicts the Northern province of Madagascar with the provincial capital Antsiranana in the centre of the image. The yellow colouring on the image clearly shows the Indian Ocean’s wave swell. The swell changes once the water streams through the narrow entrance to the Baie de Diego. In contrast to the open ocean, the water surface within the bay is very smooth and reflects the TanDEM-X radar beam evenly.

This image was acquired at 15.55 (BST) last Thursday afternoon – breaking TerraSAR-X’s world record. It took TerraSAR-X four and a half days before its first data was available, whereas it was just three days and 14 hours after its 03.14 launch on 21 June that the first images taken by Germany’s latest radar satellite were able to be downloaded. The Neustrelitz ground station received 8Gb of data.

Reservoirs, fields and a train on the move in the Ukraine

This TanDEM-X image (left) of a landscape in the Ukraine shows how a radar satellite depicts fields and forests: it shows a dam near the river Donez, a tributary of the river Don. The reservoir is surrounded by forest and agricultural areas. The fields are cultivated with a variety of crops which reflect the radar beams from space differently. This variable surface texture is represented in the image by differing brightness and colouring. East of the small reservoirs in the centre of the image a moving train is visible as a bright curv
ed line. The displacement of the train in relation to the track enables the calculation of the train’s velocity from space.

Eagle eye – 500km above Moscow

The Moscow-Sheremetyevo airport, 30km northwest of Moscow, is visible in the centre of the above right image. Terminal 1 in the north, Terminal 2 in the south and the two runways can all be seen clearly. The smooth concrete surfaces of the runways reflect the radar beam away from the satellite and therefore appear as black lines. Various expanses of water like the Pirogovskoye Reservoir and the Uchinskoye Reservoir are shown to the north of the city.

Forthcoming milestones

By the end of July both radar satellites will be brought to within 20 kilometres of each other. October will then see a further milestone – another world first – when the two satellites will be flying in formation flight above the Earth, just 200 metres apart. This will mark the beginning of the second part of the commissioning phase which will focus on the formation-flight and control aspects of both satellites. Infoterra GmbH (Germany) 2010

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