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Last updated on April 23, 2014 at 21:24 EDT
Golden Gate Bridge San Francisco
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Golden Gate Bridge, San Francisco

November 1, 2011
CHRIS's multi-angled view of Golden Gate Bridge in San Francisco, USA. For most Earth-observing satellites, image acquisition is only a matter of opening a viewing aperture but Proba-1 is different. The satellite’s platform and payload work as one: spinning reaction wheels guided by a startracker roll it up to 25º side to side and 55º along its path. This helps Proba-1 compensate for its 7.5 km/s speed, like a photographer panning to snap a moving target. In addition, Proba-1 can record up to five differently angled views of the same target, important for researchers investigating how vegetation changes appearance with shifts in view. Understanding this has proved beneficial for mapping and classifying land cover, from forest monitoring in Canada to crop yield predictions in Europe, Australia and China.