TerraSAR-X images International Space Station
DLR has released an image of the ISS taken by the German radar satellite TerraSAR-X.
The International Space Station (ISS) passed across the field-of-view of Germany's remote sensing satellite at a distance of 195 kilometres (122 miles) and at a relative speed of 34,540 kilometres per hour (over 22,000 mph). The encounter lasted for about three seconds, but this brief moment was long enough for the synthetic aperture radar on TerraSAR-X to acquire an image of the ISS, a structure measuring about 110 metres by 100 metres by 30 metres.
This image has a resolution of about one metre. In other words, objects can be depicted as discrete units - that is, shown separately – provided that they are at least one metre apart. If they are closer together, they tend to merge into a single block on a radar image. However, if they have good reflective properties, objects measuring less than one metre can be portrayed effectively. Having said that, the radar image will always enlarge them to at least one metre – there being no way around the laws of physics in this case.
TerraSAR-X is the first German satellite that has been manufactured under what is known as a Public-Private Partnership (PPP) between DLR and Astrium GmbH in Friedrichshafen. The satellite travels around Earth in a polar orbit and records unique, high-quality X-band radar data about the entire planet using its active antenna. TerraSAR-X works regardless of weather conditions, cloud cover or the absence of daylight and is able to provide radar data with a resolution down to one metre.