Landsat 7 begins viewing the world
The very first Landsat 7 image was a view of South Dakota, home of the U.S. Geological Survey data center for Landsat imagery
May 4, 1999
Web posted at: 4:15 PM EDT
NASA has released the first Landsat 7 images as the satellite begins its mission to gather data on Earth's land and coastal regions. Analysis of the data will provide scientists with new information on deforestation, receding glaciers and agriculture.
The Tennessee Valley from just east of Huntsville, Ala., to just west of Atlanta, and north to Knoxville, can be viewed in one of the first images. This area is home to the Global Hydrology and Climate Center, one of the research institutions that will use Landsat 7's improved imagery.
Scientists at the GHCC in Huntsville will use Landsat imagery to analyze urban growth in studies of the "urban heat island" effect around cities and in searching for ancient Mayan ruins in Central America.
The very first Landsat 7 image was a view of South Dakota, home of the U.S.Geological Survey data center for Landsat imagery. Project officials are pleased with the quality of the data received so far. The resolution of the new image is twice as good as previous Landsat images, distinctly highlighting airport runways, dams, cities, rivers and highways.
Landsat 7 was launched from Vandenberg Air Force Base in Florida on April 15.
The launch of Landsat 7
The satellite is part of NASA's Earth Science Enterprise, which is being built to continue the flow of global change information to users worldwide. Scientists use Landsat satellites to gather remotely sensed images of the land surface and surrounding coastal regions for global change research, regional environmental change studies and other civil and commercial purposes.
Landsat 7 carries three primary instruments, the Multispectral Scanner, the Thematic Mapper and the Enhanced Thematic Mapper. An MSS has been aboard every Landsat since the first in 1972. The TM was introduced on Landsat 4, and the ETM+ is new to Landsat 7.
By equipping the satellite with copies of older instruments, scientists can compare 27-year-old Landsat images with new images and be able to sort out effects caused by instrument differences as they analyze a scene.
The ETM+ views the Earth in three main sections of the spectrum, four visible and near infrared channels, two short wavelength infrared and thermal long wavelength infrared. Resolution of the ETM+ is 15 meters (49 feet) in black & white mode, 60 meters (197 feet) in the thermal channel, and 30 meters (98 feet) in the rest of the channels.
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