- Press Release
- Oct 31, 2023
Landsat 7 Spacecraft Celebrates First Birthday
David E. Steitz
Headquarters, Washington, DC
Goddard Space Flight Center, Greenbelt, MD
U.S. Geological Survey, Reston, VA
A year after its April 1999 launch, Landsat 7 continues to
serve a wide variety of “Earth customers” with its spectacular
data. Since being declared operational last July, Landsat 7 has
gathered more than 90,000 images, covering most of the Earth’s
surface multiple times in stunning detail.
“The resolution and absolute calibration of the imagery
collected by the Landsat 7 ‘Enhanced Thematic Mapper Plus’
instrument are better than what has been provided by previous
Landsat sensors,” said Dr. Darrel Williams, Landsat 7 Project
Scientist, at NASA’s Goddard Space Flight Center, Greenbelt, MD.
“These enhancements permit users to more easily register the image
data to maps, to resolve smaller features in the imagery and to
more confidently compare current results with those derived from
analyses of data acquired by earlier Landsat sensors.”
Landsat 7 is the latest in a continuous series of Earth
observation satellites that began with Landsat 1 in 1972. Unlike
its predecessors, Landsat 7 can create global maps of the Earth in
record time due to technology advances developed by NASA.
Landsat 7 has provided images of most major U.S. cities, as
well as timely images of the recent devastating floods in
Mozambique, the flood damage in North Carolina from Hurricane
Floyd, and the drought conditions that plagued the eastern U.S.
last summer. The imagery also has been used to monitor volcanic
eruptions in Alaska, Hawaii, Italy, Mexico and Central America.
The satellite has documented changes over time, such as receding
glaciers in Alaska and the Alps, deforestation in the tropics, and
wildfires in Siberia and the outback of Australia.
Farmers and commodity brokers have used the data to assess
and predict crop yields locally, regionally and on a global basis.
A group of scientists, led by Dr. Susan Moran of the U.S.
Department of Agriculture, is using Landsat 7 data help farmers
and land managers increase crop yields and cut costs while
reducing environmental pollution.
Scientists from NASA’s partner agency in the Landsat 7
mission, the U.S. Geological Survey (USGS), are using Landsat 7 to
determine the amount and condition of dry biomass on the ground, a
potential fuel source for wildfires that can threaten humans,
animals and natural resources. In addition, USGS scientists have
used Landsat 7 to provide a synoptic view of the landscape
simultaneously with the outbreak of infectious diseases — most
recently in the outbreak of the West Nile Virus, a mosquito-borne
disease that caused encephalitis in some residents of New York
City last summer.
“Landsat 7 is already proving to be a major source for
information about the land mass of the planet, and building on
previous satellite data provides us a long-term record of
information about the Earth,” said USGS Landsat program manager,
R. J. Thompson.
The USGS Earth Resources Observation Systems (EROS) Data
Center in Sioux Falls, SD, processes, archives, and distributes
all Landsat data to researchers and the public. Every 16 days,
Landsat 7 flies over the same geographic area and can document the
ground-cover conditions of the entire globe on a seasonal basis.
Everyday, Landsat 7 collects and downlinks 250 scenes of data to
be archived at the EROS Data Center. An additional 200 unique
scenes are sent down to nearly a dozen international ground-
receiving stations located around the world.
The spacecraft is controlled from a mission operations center
at Goddard. NASA controllers will continue to operate the
spacecraft until Oct. 1, 2000, when control will be turned over to
the U.S. Geological Survey. The U.S. Geological Survey currently
provides Landsat 7 image products to hundreds of customers each
week through an Internet site that allows visitors to preview
imagery before purchase.
Landsat 7 is part of NASA’s Earth Science Enterprise, a long-
term global research program studying human-induced and natural
changes in the Earth’s global environment.
More information on Landsat 7 can be found on the Internet
Supporting images for this press release can be found at URL:
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