NASA's Observatorium -- Observation of the Week

July 21, 1999

Landsat 7--Measuring Global Change

The first official Landsat 7 image, showing the eastern border area of South Dakota and Nebraska, including Sioux Falls (1) and the Missouri River (2).

The western part of Lake Erie, including Detroit, Michigan (1), Windsor, Ontario (2), and Toledo, Ohio (3).

The panhandle of Florida from Pensacola (1) to Fort Walton Beach (2) and Panama City (3).

Contrail above the California coast as Landsat 7 is launched from Vandenberg Air Force Base into a polar orbit, April 15, 1999.

Click on the images for larger views and additional information.

Image Credits: US Geological Survey (the three Landsat 7 images). Paul Newman, NASA Goddard Space Flight Center (Landsat 7 launch image).

Images 1-3 shown above are among the first taken by Landsat 7. They were released on April 22, 1999, by NASA and the US Geological Survey (USGS) in celebration of Earth Day.

Landsat 7 is the latest Earth-observing satellite in a series that began with Landsat 1 in 1972. Like its predecessors, Landsat 7 will obtain images of land surfaces and surrounding coastal regions for global change research, regional environmental change studies, and other civil and commercial purposes.

Earlier Landsat missions produced the first composite mosaic of the 48 contiguous United States, monitored timber losses in the US Pacific Northwest, mapped the extent of winter snow pack, measured the impact of strip mining, helped to locate mineral deposits, assessed natural changes due to fires and insect infestation, and carried out many other remote sensing studies around the globe.

Landsat 7 will improve on these and many other studies by carrying out repetitive, synoptic studies of continental surfaces in optical, infrared, and short wave bands of the electromagnetic spectrum. It will be able to resolve details as small as 98 ft. (30 meters), which is twice the capability of previous Landsat spacecraft.

Landsat 7 was launched from Vandenberg Air Force Base, CA, on April 15, 1999, by a Boeing Delta-II launch vehicle (see last image shown above). The spacecraft was launched into a 434- by 419-mile-high polar orbit. Within 70 days of launch the orbit will be adjusted to be circular with an altitude of 438 miles.

More Cool Stuff

Three US government agencies have responsibility for Landsat 7. NASA developed and launched the satellite; the National Oceanic and Atmospheric Administration (NOAA) provides ground support; and the US Geological Survey (USGS) receives, processes, archives, and distributes Landsat 7 data:: http://landsat.gsfc.nasa.gov/
For a collection of Landsat images illustrating environmental change from 1972 to the present, go to the EarthShot Web site of the USGS Earth Resources Observation Systems (EROS) Data Center near Sioux Falls, South Dakota:: http://edcwww.cr.usgs.gov/earthshots/slow/tableofcontents
Check out our Earth Day 1999 celebration Web pages, featuring articles on ozone, shrinkage of glaciers in Greenland, natural resources conservation, Earth Day links, and more:: http://observe.ivv.nasa.gov/nasa/earth/earth_day/earth_day_home.html
In July 1997, the Landsat program celebrated its 25th anniversary:: http://observe.ivv.nasa.gov/nasa/ootw/1997/ootw_971105/ob971105.html
As part of its Learning Technologies Project (LTP), NASA supports a number of educational Web sites that have excellent material on the Earth sciences, including remote sensing and environmental science data:: http://observe.ivv.nasa.gov/nasa/education/edu/edudocs/topic_land.html

Check out other observations in the Observation of the Week Archive.