Landsat 7 starts viewing the the world
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Landsat 7 starts viewing the world New satellite provides double the
detail of earlier satellites
April 28, 1999: 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 Landsat 7 images (right) released by NASA and the U.S. Geological Survey (USGS) on Earth Day.
The Tennessee Valley 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, Ala. (just barely out of this image to the left), will use Landsat imagery to help analyze urban growth in studies of the "urban heat island" effect around cities, and in searching for ancient Mayan ruins in Central America.
Right: The southeastern Tennessee Valley. The Tennessee River slices through the upper left corner of the image (Lake Guntersville is the large body of water). Chattanooga, Tenn., is visible in the upper middle portion of the image. Links to 850x925-pixel, 184KB JPG. Credit: NASA and USGS.
Left: South Dakota is shown in the first image from
Landsat 7. Links to 941x1024-pixel,
The images shown here are raw frames taken for engineering data. They have not been calibrated, so they might not fully represent the ground scene. Credit: NASA and USGS.
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Officials at the Landsat 7 Project have announced that they are"highly pleased with the quality of the ETM+ data received so far." The satellite is gathering data from Earth's land surface and coastal regions. Analysis of the data will provide scientists with new information on deforestation, receding glaciers and crop monitoring.
Landsat 7 carries a new instrument, the the Enhanced Thematic Mapper Plus (ETM+). Previous Landsat satellites carried the Multispectral Scanner (MSS) and the Thematic Mapper (TM) instruments. An MSS was flown aboard every Landsat launched since the first in 1972. The TM was introduced on Landsats 4 and 5. Replacing MSS and TM , the ETM+ greatly improves upon the earlier instruments.
Left: A contrail (condensation trail) from a jet casts a shadow over the American plains. Links to 512x257-pixel, 132KB JPG. Credit: NASA and USGS.
Because of the long history of the Landsat Program, scientists can compare the better calibrated Landsat 7 data with older Landsat images and be able to sort out effects caused by instrument differences as they analyze a scene. This will give researchers improved insight into the 27 year time series of Earth remote sensed Landsat data from previous missions, greatly enhancing the value of the entire archive.
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Landsat 7 Project home page
Southeast Regional Climate Assessment - from the Global Hydrology and Climate Center
GHCC Home page - Earth, Climate, Hydrologic, and Archaeological studies
Every day is Earth Day for climate scientists (April 22, 1999): GHCC researchers will use Landsat 7 images for a closer look at terra firma
Students to learn what's hot at Earth Day celebration (April 22, 1999): Open house at Global Hydrology and Climate Center
More Space Science Headlines - NASA research on the web
NASA's Earth Science Enterprise Information on Earth Science missions, etc.
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|For more information,
Dr. John M. Horack , Director of Science Communications
|Author: Dave Dooling|
Curator: Bryan Walls
NASA Official: John M. Horack