Showing posts with label USGS. Show all posts
Showing posts with label USGS. Show all posts

Critical Milestone Reached for 2012 Landsat Mission

GREENBELT, Md.The Operational Land Imager (OLI), built by Ball Aerospace & Technologies Corp., Boulder, Colo., has been approved by NASA Goddard Space Flight Center for shipment to Orbital Sciences Corporation, Gilbert, Ariz. for integration onto the Landsat Data Continuity Mission (LDCM) spacecraft.

"OLI will be more sensitive to land cover changes and characteristics across the landscape and over time than previous Landsat instruments," said James Irons, LDCM Project Scientist at NASA Goddard. "Analysts will be better able to identify and characterize land cover while also being better able to detect and monitor change."

A multitude of scientific, commercial and governmental users rely on Landsat as their primary source of moderate-resolution, multispectral, image data. OLI will measure Earth’s reflectance in nine portions of the spectrum, including visible light, near infrared, and shortwave infrared, providing data that scientists and others use to quantify changes in Earth’s landscapes.

OLI images will cover wide areas of the Earth's landscape while providing sufficient resolution to distinguish features like urban centers, farms, forests and other land uses. The OLI will provide Earth-imaging at 15-meter (49 ft.) panchromatic and 30-meter multispectral spatial resolutions along a 185 km (115 miles)-wide swath. The entire Earth will fall within view of the OLI once every 16 days from the near-polar LDCM orbit.

OLI represents advancement in Landsat sensor technology. Instruments on earlier Landsat satellites employed scan mirrors to sweep the instrument fields of view across the surface swath width and transmit light to a few detectors. The OLI will instead use long detector arrays, with over 7000 detectors per spectral band, aligned across its focal plane to view across the swath. The OLI design results in a more sensitive instrument providing improved land surface information with fewer moving parts. Engineers expect this new design to be more reliable while providing improved performance.

"OLI provides the key sensor technology to allow continuation of Landsat Earth observations into a fourth decade," said Ball Aerospace president and CEO, David L. Taylor. "This continuation is essential to maintain seamless acquisition of Earth-from-space images not captured by any other private or public source."

The Landsat program is a series of Earth-observing satellite missions jointly managed by NASA and the U.S. Geological Survey (USGS). For nearly 40 years, Landsat satellites have continuously and consistently collected images of Earth, creating a historical archive unmatched in quality, detail, coverage and value. Freely available Landsat data provide a unique resource for people who work in agriculture, geology, forestry, regional planning, education, mapping and global change research.

Satellite Images Display Extreme Mississippi River Flooding from Space


Recent Landsat satellite data captured by the USGS and NASA on May 10 shows the major flooding of the Mississippi River around Memphis, Tenn. and along the state borders of Tennessee, Kentucky, Missouri, and Arkansas as seen from 438 miles above the Earth.

The flood crest of 47.87 feet on May 10, is the second highest rise in recent history; the highest being 48.7 feet in 1937. Five counties surrounding Memphis have been declared disaster areas, and the costs of the flooding are expected to approach $1 billion. The Mississippi River crest continues to move south and is expected to occur in the Greenville, Miss. Area around May 16 to finally crest in New Orleans around May 23.

When natural hazards like flooding occur, USGS provides the most recent Landsat data to local emergency managers.

"Landsat imagery is crucial in helping to monitor the flood rate and effects of the flooding in the region, and to aid in the decision making process regarding flood control. Decisions such as closing portions of the Mississippi River to shipping and opening flood gates outside of low-lying New Orleans in preparation to the flood wave as it makes its way slowly down the river to the Gulf of Mexico," said Mark Anderson, Acting Director of the USGS Earth Resources Observation and Science Center.


James Irons, Landsat Data Continuity Mission (LDCM) Project Scientist at NASA Goddard Space Flight Center in Greenbelt, Md. said, "NASA Goddard has managed the development of all the successfully launched Landsat satellites and is currently developing the next Landsat satellite system, the Landsat Data Continuity Mission, in partnership with USGS." The launch of LDCM is scheduled for December, 2012.

Remotely sensed data are not the only science endeavors occurring due to floods. The USGS collects river data through its network of about 7,700 stream gauges around the Nation. You can receive instant, customized updates about water conditions, including flooding, by subscribing to USGS WaterAlert.

The scenes captured by Landsat 5 show the Mississippi River in the Memphis, Tenn. area, and along the state borders of Tennessee, Kentucky, Missouri, and Arkansas. The January images show the river before it began to flood. In the May images, the dark blue tones are water, the light green is cleared fields, and the light tones are clouds.