CNES receives first imagery from Pleiades 1

CNES receives first imagery from Pleiades 1

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France: The new French high-resolution Pleiades 1 earth-observation satellite sent down its first pictures. One of the shots released by the French space agency (CNES) is of central Paris, showing the Louvre and the Place De La Concorde – “naturellement”. The satellite was launched on December 16, 2011.
The Pleiades project has been in development for the best part of a decade. It will produce pictures that have a resolution of 50cm after processing. The satellite will give Europe a high performance capability to rival that of the US. The market for sub one metre satellite imagery has become dominated in recent years by two US companies – DigitalGlobe and GeoEye. Many of the pictures we see on Google and Bing maps are sourced from these two operators.
Pleiades will go head-to-head with the US satellites and has a number of clever tricks that should enable it to win a sizeable market share. One of these tricks is the ability to swivel its instrument in quick time to acquire a strip, or mosaic, of images around its target in a single pass overhead. So whereas the nominal maximum width in an image is 20km, Pleiades can scan the ground rapidly to effectively build up a much wider swath at any given point.
“Pleiades is equipped with control moment gyros,” explained Charlotte Gabriel Robez, the Pleiades project manager with Astrium Geo-information Services. “These devices allow Pleiades to slew very fast from a point A to a point B,” she explained.
“Imagine there is 200 km between those two locations – if you have these control moment gyros, you only need 11 seconds to switch. If you do not have them, you need around 20 seconds. This means that when you fly over a given area, you can acquire double the number of images than would normally be the case. So, we can collect either plenty of different images over a narrow area, or we can ‘paint’ a large area 100km by 100km. We can even acquire several images of the same place in the very same pass, meaning that we can build up 3D models of the ground thanks to the different viewing angles.”
A second satellite will launch in 2013 and its orbit around the globe will be off set from the first by 180 degrees. This will then allow the Pleiades system to take a picture of any place on Earth every day, assuming there’s no cloud over the target.
Source: BBC