Large Areas
For large area mosaics, or for particularly cloudy parts of the world, cloud cover can be a big problem. The image on the left shows three orbits of a weather satellite received at a ground station in central Europe during the course of one day. Even over one week, selecting the most cloud-free pixel from each image, significant cloud cover remains (middle). Our cloud-free mosaic of Europe (right) required more than a hundred carefully-selected images acquired over a period of two years.