When I use the center on city or landmark feature in the image viewer, why is the image black over some locations?
Black areas are regions where no data are available. In order to collect data from the satellite, the satellite must be in view of our satellite dish. (Imagine a large circle centered on Corvallis, Oregon). The data we collect is what the satellite is seeing directly beneath it as it passes inside our viewing circle. We can usually see the satellite two to three times as it flies over, covering different areas of our viewing circle. The satellites we use (TERRA and AQUA) don't fly over the exact same place every day - they shift slightly. It takes 16 days before the satellite flies over the exact same location again. Near our satellite dish (Corvallis, Oregon), data will be available every day. However near the edge of our viewing circle (like Minnesota), data will be available only intermittently. So check back again another day if no data are currently available over your city or landmark of interest!
|
