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The Landsat Project is a joint initiative of the U.S. Geological Survey (USGS) and the National Aeronautics and Space Administration (NASA) to gather Earth resource data using a series of satellites. The Landsat Project began in the early 1970s. Since then, many different satellites have been sent into orbit. These satellites have also taken UK satellite photos.
While most of the satellites are not in operation now, Landsat 5 and Landsat 7 are still working around the clock to archive Earth's rapidly changing landscape.
Landsat 7 was launched on April 15, 1999 from the Western Test Range at Vandenberg Air Force Base on a Delta-II launch vehicle. At launch, the satellite weighed approximately 4,800 pounds (2,200 kilograms). The spacecraft is about 14 feet long (4.3 meters) and 9 feet (2.8 meters) in diameter.
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The satellite orbits the Earth at an altitude of approximately 438 miles (705 kilometres) with a sun-synchronous 98-degree inclination and a descending equatorial crossing time of 10 a.m.
Mosaic Product Specifications:
Spectral Bands
Three Landsat ETM+ bands, each sharpened with the panchromatic band.
Band 7 (mid-infrared light) is displayed as red
Band 4 (near-infrared light) is displayed as green
Band 2 (visible green light) is displayed as blue
Pixel size: 14.25 meters, Absolute Positional Accuracy: ±75 meters RMSE.
Coverage Date: July 1999 to Sept 2002.
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Mosaic Colours:
Combining bands 7, 4, and 2 (one visible and two infrared channels) results in a false colour image where vegetation appears as bright to dark green. Forested areas are generally dark green while herbaceous vegetation is light green. Rangeland or more open areas appear pink to light purple. Areas with extensive pavement or urban development appear light blue or white to purple. Less densely-developed residential areas appear light green and golf courses are very bright green. Shallow water areas or those areas with snow appear blue.
