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1

Perspective View with Landsat Overlay, Los Angeles Basin  

NASA Technical Reports Server (NTRS)

Most of Los Angeles is visible in this computer-generated north-northeast perspective viewed from above the Pacific Ocean. In the foreground the hilly Palos Verdes peninsula lies to the left of the harbor at Long Beach, and in the middle distance the various communities that comprise the greater Los Angeles area appear as shades of grey and white. In the distance the San Gabriel Mountains rise up to separate the basin from the Mojave Desert, which can be seen near the top of the image.

This 3-D perspective view was generated using topographic data from the Shuttle Radar Topography Mission (SRTM) and an enhanced color Landsat 5satellite image mosaic. Topographic expression is exaggerated one and one-half times.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and will substantially help in analyzing the large and growing Landsat image archive.

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR)that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C.

Size: View width 70 kilometers (42 miles), View distance 160 kilometers(100 miles) Location: 34.0 deg. North lat., 118.2 deg. West lon. Orientation: View north-northeast Image Data: Landsat Bands 3, 2, 1 as red, green, blue, respectively Date Acquired: February 2000 (SRTM)

2002-01-01

2

Perspective view, Landsat overlay Pasadena, California  

NASA Technical Reports Server (NTRS)

This image shows a perspective view of the area around Pasadena, California, just north of Los Angeles. The cluster of hills surrounded by freeways on the left is the Verdugo Hills, which lie between the San Gabriel Valley in the foreground and the San Fernando Valley in the upper left. The San Gabriel Mountains are seen across the top of the image, and parts of the high desert near the city of Palmdale are visible along the horizon on the right. Several urban features can be seen in the image. NASA's Jet Propulsion Laboratory (JPL) is the bright cluster of buildings just right of center; the flat tan area to the right of JPL at the foot of the mountains is a new housing development devoid of vegetation. Two freeways (the 210 and the 134) cross near the southeastern end of the Verdugo Hills near a white circular feature, the Rose Bowl. The commercial and residential areas of the city of Pasadena are the bright areas clustered around the freeway. These data will be used for a variety of applications including urban planning and natural hazard risk analysis.

This type of display adds the important dimension of elevation to the study of land use and environmental processes as observed in satellite images. The perspective view was created by draping a Landsat satellite image over an SRTM elevation model. Topography is exaggerated 1.5 times vertically. The Landsat image was provided by the United States Geological Survey's Earth Resources Observations Systems (EROS) Data Center, Sioux Falls, South Dakota.

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11,2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise,Washington, DC.

Size: Varies in a perspective view Location: 34.18 deg. North lat., 118.16 deg. West lon. Orientation: Looking Northwest Original Data Resolution: SRTM and Landsat: 30 meters (99 feet) Date Acquired: February 16, 2000

2000-01-01

3

Perspective View with Landsat Overlay, Costa Rica  

NASA Technical Reports Server (NTRS)

This perspective view shows the Caribbean coastal plain of Costa Rica, with the Cordillera Central rising in the background and the Pacific Ocean in the distance. The prominent river in the center of the image is the Rio Sucio, which merges with the Rio Sarapiqui at the bottom of the image and eventually joins with Rio San Juan on the Nicaragua border.

Like much of Central America, Costa Rica is generally cloud covered so very little satellite imagery is available. The ability of the Shuttle Radar Topography Mission (SRTM) instrument to penetrate clouds and make three-dimensional measurements will allow generation of the first complete high-resolution topographic map of the entire region. These data were used to generate the image.

This three-dimensional perspective view was generated using elevation data from SRTM and an enhanced false-color Landsat 7 satellite image. Colors are from Landsat bands 5, 4, and 2 as red, green and blue, respectively. Topographic expression is exaggerated two times.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive. The Landsat 7 Thematic Mapper image used here was provided to the SRTM by the United States Geological Survey, Earth Resources Observation Systems (EROS) Data Center, Sioux Falls, S.D.

Elevation data used in this image was acquired by the SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C.

Size: scale varies in this perspective image Location: 10.4 degrees North latitude, 84.0 degrees West longitude Orientation: looking Southwest Image Data: Landsat Bands 5, 4, 3 as red, green, blue respectively Original Data Resolution: SRTM 30 meters (99 feet) Date Acquired: February 2000 (SRTM)

2002-01-01

4

Anaglyph, Landsat Overlay: Wellington, New Zealand  

NASA Technical Reports Server (NTRS)

Wellington, the capital city of New Zealand, is located on the shores of Port Nicholson, a natural harbor at the south end of North Island. The city was founded in 1840 by British emigrants and now has a regional population of more than 400,000 residents. As seen here, the natural terrain imposes strong control over the urban growth pattern. Rugged hills generally rising to 300 meters (1,000 feet) help protect the city and harbor from strong winter winds.

New Zealand is seismically active and faults are readily seen in the topography. The Wellington Fault forms the straight northwestern (upper left) shoreline of the harbor. Toward the southwest (lower left) the fault crosses through the city, then forms linear canyons in the hills before continuing offshore. Toward the northeast (upper right) the fault forms the sharp mountain front along the northern edge of the heavily populated Hutt Valley.

This anaglyph was generated by first draping a Landsat Thematic Mapper image over a topographic map from the Shuttle Radar Topography Mission, then using the topographic data to create two differing perspectives, one for each eye. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter.

Landsat satellites have provided visible light and infrared images of the Earth continuously since 1972. SRTM topographic data match the 30 meter (99 foot) spatial resolution of most Landsat images and will provide a valuable complement for studying the historic and growing Landsat data archive. The Landsat 7 Thematic Mapper image used here was provided to the SRTM project by the United States Geological Survey, Earth Resources Observation Systems (EROS) data Center, Sioux Falls, South Dakota.

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11,2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise,Washington, DC.

Size: 31 by 23 kilometers (19 by 14 miles) Location: 41.3 deg. South lat., 174.9 deg. East lon. Orientation: North toward the top Image Data: Combination of Landsat bands 1, 2, 3, and 8 Original Data Resolution: SRTM 30 meters (99 feet); Landsat 15 meters (50 feet) Date Acquired: February 20, 2000 (SRTM); September 29, 1999 (Landsat)

2000-01-01

5

Anaglyph with Landsat Overlay, Mount Meru, Tanzania  

NASA Technical Reports Server (NTRS)

Mount Meru is an active volcano located just 70 kilometers (44 miles) west of Mount Kilimanjaro. It reaches 4,566 meters (14,978 feet) in height but has lost much of its bulk due to an eastward volcanic blast sometime in its distant past, perhaps similar to the eruption of Mount Saint Helens in Washington State in 1980. Mount Meru most recently had a minor eruption about a century ago. The several small cones and craters seen in the vicinity probably reflect numerous episodes of volcanic activity. Mount Meru is the topographic centerpiece of Arusha National Park, but Ngurdoto Crater to the east (image top) is also prominent. The fertile slopes of both volcanoes rise above the surrounding savanna and support a forest that hosts diverse wildlife, including nearly 400 species of birds, and also monkeys and leopards, while the floor of Ngurdoto Crater hosts herds of elephants and buffaloes.

The stereoscopic effect of this anaglyph was created by first draping a Landsat satellite image over a digital elevation data from the Shuttle Radar Topography Mission (SRTM), and then generating two differing perspectives, one for each eye. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and will substantially help in analyzing the large and growing Landsat image archive, managed by the U.S. Geological Survey (USGS).

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C.

Size: 37.1 kilometers (23.0 miles) by 20.3 kilometers (12.6 miles) Location: 3.2 degrees South latitude, 36.7 degrees East longitude Orientation: East at top Image Data: Landsat Bands 1, 2, 3, and 4 blended as gray. Original Data Resolution: SRTM 1 arc-second (30 meters or 98 feet) Date Acquired: February 2000 (SRTM), February 21, 2000 (Landsat 7)

2002-01-01

6

Perspective with Landsat Overlay, Mount Kilimanjaro, Tanzania  

NASA Technical Reports Server (NTRS)

Mount Kilimanjaro (Kilima Njaro or 'shining mountain' in Swahili), the highest point in Africa, reaches 5,895 meters (19,340 feet) above sea level, tall enough to maintain a permanent snow cap despite being just 330 kilometers (210 miles) south of the equator. It is the tallest free-standing mountain on the Earth's land surface world, rising about 4,600 meters (15,000 feet) above the surrounding plain. Kilimanjaro is a triple volcano (has three peaks) that last erupted perhaps more than 100,000 years ago but still exudes volcanic gases. It is accompanied by about 20 other nearby volcanoes, some of which are seen to the west (left) in this view, prominently including Mount Meru, which last erupted only about a century ago. The volcanic mountain slopes are commonly fertile and support thick forests, while the much drier grasslands of the plains are home to elephants, lions, and other savanna wildlife.

This 3-D perspective view was generated using topographic data from the Shuttle Radar Topography Mission (SRTM), a Landsat 7 satellite image, and a false sky. Topographic expression is vertically exaggerated two times.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and will substantially help in analyzing the large and growing Landsat image archive, managed by the U.S. Geological Survey (USGS).

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C.

Size: View width 124 kilometers (77 miles), View distance 166 kilometers (103 miles) Location: 3 degrees South latitude, 37 degrees East longitude Orientation: View North, 2 degrees below horizontal, 2 times vertical exaggeration Image Data: Landsat Bands 3, 2+4, 1 as red, green, blue, respectively. Original Data Resolution: SRTM 1 arc-second (30 meters or 98 feet), Thematic Mapper 30 meters (98 feet) Date Acquired: February 2000 (SRTM), A February 21, 2000 (Landsat 7)

2002-01-01

7

Anaglyph with Landsat Overlay, Kamchatka Peninsula, Russia  

NASA Technical Reports Server (NTRS)

This 3-D anaglyph shows an area on the western side of the volcanically active Kamchatka Peninsula, Russia. Red-blue glasses are required to see the 3-D effect. The topographic data are from the first C-band mapping swath of the Shuttle Radar Topography Mission (SRTM). Images from the optical Landsat satellite are overlain on the SRTM topography data. The meandering channel of the Tigil River is seen along the bottom of the image, at the base of steep cliffs. In the middle left of the image, a terrace indicates recent uplift of the terrain and downcutting by the river. High resolution SRTM topographic data will be used by geologists and hydrologists to study the interplay of tectonic uplift and erosion.

This anaglyph was generated using topographic data from the Shuttle Radar Topography Mission to create two differing perspectives of a single image, one perspective for each eye. Each point in the image is shifted slightly, depending on its elevation. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter. The United States Geological Survey's Earth Resources Observations Systems (EROS) Data Center, Sioux Falls, South Dakota, provided the Landsat data, which are overlain on the topography.

The Shuttle Radar Topography Mission (SRTM), launched on February 11,2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission is designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, an additional C-band imaging antenna and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) and the German (DLR) and Italian (ASI) space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC.

Size: 5.3 km (3.3 miles) x 6.0 km (3.7 miles) Location: 57 deg. North lat., 159 deg. East lon. Orientation: North at left Original Data Resolution: SRTM 30 meters (99 feet); Landsat 15 meters (45 feet) Date Acquired: February 12, 2000

2000-01-01

8

SRTM Perspective View with Landsat Overlay: Mt. Pinos, California  

NASA Technical Reports Server (NTRS)

Prominently displayed in this image, Mt. Pinos, at 2,692 meters (8,831 feet) is the highest peak in the Los Padres National Forest. Named for the mantle of pine trees covering its slopes and summit, it offers one of the best stargazing sites in Southern California. Shuttle Radar Topography Mission (SRTM) elevation data were combined with Landsat data to generate this perspective view looking toward the northwest. Not only is the mountain popular with astronomers and astro-photographers, it is also popular for hiking trails and winter sports.

The broad low relief area in the right foreground is Cuddy Valley. Cuddy Valley Road is the bright line on the right (north)side of the valley. Just to the left and paralleling the road is a scarp (cliff) formed by the San Andreas fault. The fault slices through the mountains here and then bends and continues onto the Carrizo Plain (right center horizon). This entire segment of the San Andreas fault broke in a major earthquake in 1857.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data match the 30-meter(98-foot) resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive. For visualization purposes, topographic heights displayed in this image are exaggerated two times. Colors approximate natural colors.

The elevation data used in this image was acquired by SRTM aboard Space Shuttle Endeavour, launched on February 11,2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60 meters (about 200 feet)long, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena.

Distance to Horizon: 176 kilometers (109 miles) Location: 34.8 deg. North lat., 119.1 deg. West lon. View: Toward the Northwest Date Acquired: February 16, 2000 SRTM, December 14, 1984 Landsat

2001-01-01

9

Perspective view, Landsat overlay San Andreas Fault, Palmdale, California  

NASA Technical Reports Server (NTRS)

The prominent linear feature straight down the center of this perspective view is the San Andreas Fault. This segment of the fault lies near the city of Palmdale, California (the flat area in the right half of the image) about 60 kilometers (37 miles) north of Los Angeles. The fault is the active tectonic boundary between the North American plate on the right, and the Pacific plate on the left. Relative to each other, the Pacific plate is moving away from the viewer and the North American plate is moving toward the viewer along what geologists call a right lateral strike-slip fault. Two large mountain ranges are visible, the San Gabriel Mountains on the left and the Tehachapi Mountains in the upper right. The Lake Palmdale Reservoir, approximately 1.5 kilometers (0.9 miles) across, sits in the topographic depression created by past movement along the fault. Highway 14 is the prominent linear feature starting at the lower left edge of the image and continuing along the far side of the reservoir. The patterns of residential and agricultural development around Palmdale are seen in the Landsat imagery in the right half of the image. SRTM topographic data will be used by geologists studying fault dynamics and landforms resulting from active tectonics.

This type of display adds the important dimension of elevation to the study of land use and environmental processes as observed in satellite images. The perspective view was created by draping a Landsat satellite image over an SRTM elevation model. Topography is exaggerated 1.5 times vertically. The Landsat image was provided by the United States Geological Survey's Earth Resources Observations Systems (EROS) Data Center, Sioux Falls, South Dakota.

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11,2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise,Washington, DC.

Size: Varies in a perspective view Location: 34.58 deg. North lat., 118.13 deg. West lon. Orientation: Looking Northwest Original Data Resolution: SRTM and Landsat: 30 meters (99 feet) Date Acquired: February 16, 2000

2000-01-01

10

Perspective View with Landsat Overlay, Mount Shasta, Calif.  

NASA Technical Reports Server (NTRS)

The volcanic nature of Mount Shasta is clearly evident in this computer-generated perspective viewed from the northwest. At over 4,300 meters (14,000 feet), Mount Shasta is California's tallest volcano and part of the Cascade chain of volcanoes extending south from Washington. The twin summits of Shasta and Shastina tower over a lava flow on the flank of the volcano. Cutting across the lava flow is the bright line of a railroad. The bright area at the right edge is the town of Weed.

This 3-D perspective view was generated using topographic data from the Shuttle Radar Topography Mission (SRTM) and an enhanced false-color Landsat 5 satellite image. Colors are from Landsat bands 3, 2, and 1 as red, green and blue, respectively. Topographic expression is exaggerated two times.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and will substantially help in analyzing the large and growing Landsat image archive.

The Landsat Thematic Mapper image used here came from an online mosaic of Landsat images for the continental United States (http://mapus.jpl.nasa.gov), a part of NASA's Digital Earth effort.

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C.

Size: scale varies in this perspective image Location: 41.4 degrees North latitude, 122.3 degrees West longitude Orientation: looking southeast Image Data: Landsat Bands 3, 2, 1 as red, green, blue, respectively Original Data Resolution: SRTM 1 arcsecond (30 meters or 98 feet) Thematic Mapper 1 arcsecond (30 meters or 98 feet) Date Acquired: February 2000 (SRTM)

2002-01-01

11

Perspective View with Landsat Overlay, San Jose, Costa Rica  

NASA Technical Reports Server (NTRS)

This perspective view shows the capital city of San Jose, Costa Rica, the gray area in the center of the image. The view is toward the northwest with the Pacific Ocean in the distance and shows a portion of the Meseta Central (Central Valley), home to about a third of Costa Rica's population.

Like much of Central America, Costa Rica is generally cloud covered, so very little satellite imagery is available. The ability of the Shuttle Radar Topography Mission (SRTM) instrument to penetrate clouds and make three-dimensional measurements will allow generation of the first complete high-resolution topographic map of the entire region. These data were used to generate the image.

This three-dimensional perspective view was generated using elevation data from SRTM and an enhanced false-color Landsat 7 satellite image. Colors are from Landsat bands 5, 4, and 2 as red, green and blue, respectively. Topographic expression is exaggerated two times.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive. The Landsat 7 Thematic Mapper image used here was provided to the SRTM by the United States Geological Survey, Earth Resources Observation Systems (EROS) Data Center, Sioux Falls, S.D.

Elevation data used in this image was acquired by the SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C.

Size: scale varies in this perspective image Location: 10.0 degrees North latitude, 83.8 degrees West longitude Orientation: looking Northwest Image Data: Landsat Bands 5, 4, 3 as red, green, blue respectively Original Data Resolution: SRTM 30 meters (99 feet) Date Acquired: February 2000 (SRTM)

2002-01-01

12

Perspective View with Landsat Overlay, San Francisco Bay Area, Calif.  

NASA Technical Reports Server (NTRS)

The cities of San Francisco and the East Bay are highlighted in this computer-generated perspective viewed from west of the Golden Gate. San Francisco occupies the peninsula jutting into the picture from the right. Golden Gate Park is the long rectangle near its left end and the Presidiois the green area at its tip, from which Golden Gate Bridge crosses to Marin. Treasure Island is the bright spot above San Francisco and Alcatraz Island is the small smudge below and to the left. Across the bay from San Francisco lie Berkeley (left) and Oakland (right). Mount Diablo, a landmark visible for many miles, rises in the distance at the upper right.

This three-dimensional perspective view was generated using topographic data from the Shuttle Radar Topography Mission (SRTM) and an enhanced false-color Landsat 5 satellite image. Colors are from Landsat bands 3, 2, and 1 as red, green and blue, respectively. Topographic expression is exaggerated two times.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and will substantially help in analyzing the large and growing Landsat image archive.

The Landsat Thematic Mapper image used here came from an on-line mosaic of Landsat images for the continental United States (http://mapus.jpl.nasa.gov), a part of NASA's Digital Earth effort.

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, DC.

Size: scale varies in this perspective image Location: 37.5 deg. North lat., 122.3 deg. West lon. Orientation: looking west Image Data: Landsat Bands 3, 2, 1 as red, green, blue, respectively Original Data Resolution: SRTM 1 arcsecond (30 meters or 98 feet), Thematic Mapper 1 arcsecond (30 meters or 98 feet) Date Acquired: February 2000 (SRTM)

2002-01-01

13

Perspective View with Landsat Overlay, San Francisco Bay Area, Calif.  

NASA Technical Reports Server (NTRS)

The defining landmarks of San Francisco, its bay and the San Andreas Fault are clearly seen in this computer-generated perspective viewed from the south. Running from the bottom of the scene diagonally up to the left, the trough of the San Andreas Fault is occupied by Crystal Springs Reservoir and San Andreas Lake. Interstate 280 winds along the side of the fault. San Francisco International Airport is the angular feature projecting into the bay just below San Bruno Mountain, the elongated ridge cutting across the peninsula. The hills of San Francisco can be seen beyond San Bruno Mountain and beyond the city, the Golden Gate.

This 3-D perspective view was generated using topographic data from the Shuttle Radar Topography Mission (SRTM) and an enhanced color Landsat 5satellite image. Topographic expression is exaggerated two times.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and will substantially help in analyzing the large and growing Landsat image archive.

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on Feb. 11,2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C.

Size: scale varies in this perspective image Location: 37.5 deg. North lat., 122.3 deg. West lon. Orientation: looking north Image Data: Landsat Bands 3,2,1 as red, green, blue, respectively Original Data Resolution: SRTM 1 arcsecond (30 meters or 98 feet), Thematic Mapper 1 arcsecond (30 meters or 98 feet) Date Acquired: February 2000 (SRTM)

2002-01-01

14

Perspective View with Landsat Overlay, San Diego, Calif.  

NASA Technical Reports Server (NTRS)

The influence of topography on the growth of the city of San Diego is seen clearly in this computer-generated perspective viewed from the south. The Peninsular Ranges to the east of the city have channeled development of the cities of La Mesa and El Cajon, above the center. San Diego itself clusters around the bay enclosed by Point Loma and Coronado Island. In the mountains to the right, Lower Otay Lake and Sweetwater Reservoir are the dark patches.

This 3-D perspective view was generated using topographic data from the Shuttle Radar Topography Mission (SRTM) and an enhanced color Landsat 5satellite image. Topographic expression is exaggerated two times.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and will substantially help in analyzing the large and growing Landsat image archive.

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR)that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C.

Size: scale varies in this perspective image Location: 32.6 deg. North lat., 117.1 deg. West lon. Orientation: looking north Image Data: Landsat Bands 3, 2, 1 as red, green, blue, respectively Original Data Resolution: SRTM 1 arcsecond (30 meters or 98 feet), Thematic Mapper 1 arcsecond (30 meters or 98 feet) Date Acquired: February 2000 (SRTM)

2002-01-01

15

Perspective View with Landsat Overlay, Mount Shasta, Calif.  

NASA Technical Reports Server (NTRS)

At more than 4,300 meters (14,000 feet ), Mount Shasta is California's tallest volcano and part of the Cascade chain of volcanoes extending south from Washington. This computer-generated perspective viewed from the west also includes Shastina, a slightly smaller volcanic cone left of Shasta's summit and Black Butte, another volcano in the right foreground.

This 3-D perspective view was generated using topographic data from the Shuttle Radar Topography Mission (SRTM) and an enhanced color Landsat 5satellite image. Topographic expression is exaggerated two times.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and will substantially help in analyzing the large and growing Landsat image archive.

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR)that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise,Washington, D.C.

Size: scale varies in this perspective image Location: 41.4 deg. North lat., 122.3 deg. West lon. Orientation: looking east Image Data: Landsat Bands 3,2,1 as red, green, blue, respectively Original Data Resolution: SRTM 1 arcsecond (30 meters or 98 feet), Thematic Mapper 1 arcsecond (30 meters or 98 feet) Date Acquired: February 2000 (SRTM)

2002-01-01

16

SRTM Perspective View with Landsat Overlay: Santa Barbara Coastline, California  

NASA Technical Reports Server (NTRS)

This image of the Santa Barbara, California, region provides a beautiful snapshot of the area's rugged mountains and long and varied coastline. Generated using data acquired from the Shuttle Radar Topography Mission (SRTM) and an enhanced Landsat image this is a perspective view toward the northeast, from the Goleta Valley in the foreground to a snow-capped Mount Abel (elevation 2,526 m or 8,286 feet) along the skyline at the left. On a clear day, a pilot might see a similar view shortly before touching down on the east-west runway of the Santa Barbara Airport, seen just to the left of the coastline near the center of image. This area is one of the few places along the U.S. West Coast where because of a south-facing beach, fall and winter sunrises occur over the ocean.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data match the 30-meter(98-foot) resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive. For visualization purposes, topographic heights displayed in this image are exaggerated two times. Colors approximate natural colors.

The elevation data used in this image was acquired by SRTM aboard Space Shuttle Endeavour, launched on February 11,2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60 meters (about 200-feet)long, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif, for NASA's Earth Science Enterprise, Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena.

Location: 34.5 deg. North lat., 119.75 deg. West lon. View: Northeast Scale: Scale Varies in this Perspective Date Acquired: February 16, 2000 SRTM, December 14, 1984 Landsat

2001-01-01

17

SRTM Perspective View with Landsat Overlay: Santa Barbara, California  

NASA Technical Reports Server (NTRS)

Santa Barbara, California, is often called 'America's Riviera.' It enjoys a Mediterranean climate, a mountain backdrop, and a long and varied coastline. This perspective view of the Santa Barbara region was generated using data from the Shuttle Radar Topography Mission (SRTM) and an enhanced Landsat satellite image. The view is toward the northeast, from the Goleta Valley in the foreground to a snow-capped Mount Abel (elevation 2526 m or 8286 feet) along the skyline. The coast here generally faces south. Consequently, Fall and Winter sunrises occur over the ocean, which is unusual for the U.S. west coast. The Santa Barbara 'back country' is very rugged and largely remains as undeveloped wilderness and an important watershed for local communities. Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data match the 30-meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive. For visualization purposes, topographic heights displayed in this image are exaggerated two times. Colors approximate natural colors.

The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's land surface.

To collect the 3-D SRTM data, engineers added a mast 60 meters (about 200-feet) long, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif, for NASA's Earth Science Enterprise,Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena.

Location (Isla Vista): 34.41 deg. North lat., 119.85 deg. West lon. View: East Scale: Scale Varies in this Perspective Date Acquired: February 16, 2000 SRTM, December 14, 1984 Landsat

2001-01-01

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Perspective View with Landsat Overlay, Palm Springs, Calif.  

NASA Technical Reports Server (NTRS)

The city of Palm Springs nestles at the base of Mount San Jacinto in this computer-generated perspective viewed from the east. The many golf courses in the area show up as irregular green areas while the two prominent lines passing through the middle of the image are Interstate 10 and the adjacent railroad tracks. The San Andreas Fault passes through the middle of the sandy Indio Hills in the foreground.

This 3-D perspective view was generated using topographic data from the Shuttle Radar Topography Mission (SRTM) and an enhanced color Landsat 5satellite image. Topographic expression is exaggerated two times.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and will substantially help in analyzing the large and growing Landsat image archive.

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR)that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise,Washington, D.C.

Size: scale varies in this perspective image Location: 33.8 deg. North lat., 116.3 deg. West lon. Orientation: looking west Image Data: Landsat Bands 3, 2, 1 as red, green, blue, respectively Original Data Resolution: SRTM 1 arcsecond (30 meters or 98 feet), Thematic Mapper 1 arcsecond (30 meters or 98 feet) Date Acquired: February 2000 (SRTM)

2002-01-01

19

Perspective View with Landsat Overlay, Lakes Managua and Nicaragua  

NASA Technical Reports Server (NTRS)

This perspective view shows Lakes Managua and Nicaragua near the Pacific coast of Nicaragua. Lake Managua is the 65-kilometer (40-mile)-long fresh water lake in the foreground of this south-looking view, emptying via the Tipitapa River into the much larger Lake Nicaragua in the distance. The capital city of Managua, with a population of more than 500,000, is located along the southern shore of Lake Managua, the area with the highest population density in Nicaragua.

The physical setting of Lake Managua is dominated by the numerous volcanic features aligned in a northwest-southeast axis. The cone-like feature in the foreground is Momotombo, a 1,280-meter (4,199-foot)-high stratovolcano located on the northwest end of the lake. Two water-filled volcanic craters (Apoyegue and Jiloa volcanoes) reside on the Chiltepe Peninsula protruding into the lake from the west. Two volcanoes can also be seen on the island of Ometepe in Lake Nicaragua: El Maderas rising to 1,394 meters (4,573 feet) and the active El Conception at 1,610 meters (5,282 feet).

This three-dimensional perspective view was generated using topographic data from the Shuttle Radar Topography Mission (SRTM) and an enhanced false-color Landsat 7 satellite image. Colors are from Landsat bands 5, 4, and 2 as red, green and blue, respectively. Topographic expression is exaggerated two times.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive. The Landsat 7 Thematic Mapper image used here was provided to the SRTM by the United States Geological Survey, Earth Resources Observation Systems (EROS) Data Center, Sioux Falls, S.D.

Elevation data used in this image was acquired by the SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C.

Size: scale varies in this perspective image Location: 12.1 degrees North latitude, 86.1degrees West longitude Orientation: looking South Image Data: Landsat bands 5, 4, 3 as red, green, blue respectively Original Data Resolution: SRTM 30 meters (99 feet) Date Acquired: February 2000 (SRTM)

2002-01-01

20

SRTM Perspective View with Landsat Overlay: San Jose, Costa Rica  

NASA Technical Reports Server (NTRS)

This perspective view shows the capital city of San Jose, Costa Rica, in the right center of the image (gray area). Rising behind it are the volcanoes Irazu, 3402 meters high (11,161 feet) and Turrialba, 3330 meters high (10,925 feet.)

Irazu is the highest volcano in Costa Rica and is located in the Irazu Volcano National Park, established in 1955. There have been at least 23 eruptions of Irazu since 1723, the most recent during 1963 to 1965. This activity sent tephra and secondary mudflows into cultivated areas, caused at least 40 deaths, and destroyed 400 houses and some factories.

This image was generated in support of the Central American Commission for Environment and Development through an agreement with NASA. The Commission involves eight nations working to develop the Mesoamerican Biological Corridor, an effort to study and preserve some of the most biologically diverse regions of the planet.

This three-dimensional perspective view was generated using topographic data from the Shuttle Radar Topography Mission (SRTM) and an enhanced false-color Landsat 7 satellite image. Colors are from Landsat bands 5, 4, and 2 as red, green and blue, respectively. Topographic expression is exaggerated 2X.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive. The Landsat 7 Thematic Mapper image used here was provided to the SRTM by the United States Geological Survey, Earth Resources Observation Systems (EROS) Data Center, Sioux Falls, South Dakota.

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11,2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise,Washington, DC.

Size: scale varies in this perspective image Location: 10.0 deg. North lat., 83.8 deg. East lon. Orientation: looking Southeast Image Data: Landsat Bands 5, 4, 3 as red, green, blue respectively Original Data Resolution: SRTM 30 meters (99 feet) Date Acquired: February, 2000 (SRTM)

2001-01-01

21

SRTM Anaglyph with Landsat Overlay: Miquelon and Saint Pierre Islands  

NASA Technical Reports Server (NTRS)

This anaglyph satellite image shows Miquelon and Saint Pierre Islands, located south of Newfoundland, Canada. These islands are a self-governing territory of France. A 'tombolo' (sand bar) unites Grande Miquelon to the north and Petite Miquelon to the south. Saint Pierre Island, located to the lower right, includes a harbor, an airport, and a small town. Glaciers once covered these islands and the direction of glacial flow is evident in the topography as striations and shoreline trends running from the upper right to the lower left. The darkest image features are freshwater lakes that fill glacially carved depressions and saltwater lagoons that are bordered by barrier beaches. The lakes and the lagoons are fairly calm waters and reflect less sunlight than do the wave covered and sediment laden nearshore ocean currents.

The stereoscopic effect was created by first draping a Landsat satellite image over preliminary digital elevation data from the Shuttle Radar Topography Mission (SRTM), and then generating two differing perspectives, one for each eye. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and cover the right eye with a blue filter.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive. The Landsat 7 Thematic Mapper image used here was provided to the SRTM project by the United States Geological Survey, Earth Resources Observation Systems (EROS) DataCenter, Sioux Falls, South Dakota.

The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60-meters (about 200-feet)long, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington DC.

Size: 48 by 38 kilometers (30 by 24 miles) Location: 47 deg. North lat., 56.3 deg. West lon. Orientation: North toward the upper left Image Data: Landsat bands 2 and 4 averaged Date Acquired: February 12, 2000 (SRTM), September 1, 1999 (Landsat) Image: NASA/JPL/NIMA

2000-01-01

22

Stereo Pair with Landsat Overlay, Mount Meru, Tanzania  

NASA Technical Reports Server (NTRS)

Mount Meru is an active volcano located just 70 kilometers (44 miles)west of Mount Kilimanjaro. It reaches 4,566 meters (14,978 feet) in height but has lost much of its bulk due to an eastward volcanic blast sometime in its distant past, perhaps similar to the eruption of Mount Saint Helens in Washington State in 1980. Mount Meru most recently had a minor eruption about a century ago. The several small cones and craters seen in the vicinity probably reflect numerous episodes of volcanic activity. Mount Meru is the topographic centerpiece of Arusha National Park, but Ngurdoto Crater to the east (image top) is also prominent. The fertile slopes of both volcanoes rise above the surrounding savanna and support a forest that hosts diverse wildlife, including nearly 400 species of birds, and also monkeys and leopards, while the floor of Ngurdoto Crater hosts herds of elephants and buffaloes.

This stereoscopic image was generated by draping a Landsat satellite image over a Shuttle Radar Topography Mission digital elevation model. Two differing perspectives were then calculated, one for each eye. They can be seen in 3-D by viewing the left image with the right eye and the right image with the left eye (cross-eyed viewing or by downloading and printing the image pair and viewing them with a stereoscope. When stereoscopically merged, the result is a vertically exaggerated view of Earth's surface in its full three dimensions.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot)resolution of most Landsat images and will substantially help in analyzing the large and growing Landsat image archive, managed by the U.S. Geological Survey (USGS).

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C.

Size: 37.1 kilometers (23.0 miles) by 20.3 kilometers (12.6 miles) Location: 3.2 degrees South latitude, 36.7 degrees East longitude Orientation: East at top Image Data: Landsat Bands 3, 2+4, 1 as red, green, blue, respectively. Original Data Resolution: SRTM 1 arc-second (30 meters or 98 feet) Date Acquired: February 2000 (SRTM), February 21, 2000 (Landsat 7)

2002-01-01

23

Perspective with Landsat Overlay: Mojave to Ventura, California  

NASA Technical Reports Server (NTRS)

Southern California's dramatic topography plays acritical role in its climate, hydrology, ecology, agriculture, and habitability. This image of Southern California, from the desert at Mojave to the ocean at Ventura, shows a variety of landscapes and environments. Winds usually bring moisture to this area from the west, moving from the ocean, across the coastal plains, to the mountains, and then to the deserts. Most rainfall occurs as the air masses rise over the mountains and cool with altitude. Continuing east, and now drained of their moisture, the air masses drop in altitude and warm as they spread across the desert. The mountain rainfall supports forest and chaparral vegetation, seen here, and also becomes ground water and stream flow that supports citrus, avocado, strawberry, other crops, and a large and growing population on the coastal plains.

This perspective view was generated by draping a Landsat satellite image over a preliminary topographic map from the Shuttle Radar Topography Mission. It shows the Tehachapi Mountains in the right foreground, the city of Ventura on the coast at the distant left, and the eastern most Santa Ynez Mountains forming the skyline at the distant right.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30 meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive.

The elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington DC.

Size: 43 kilometers (27 miles) view width, 166 kilometers (103 miles) view distance Location: 34.8 deg. North lat., 118.8 deg. West lon. Orientation: View toward the southwest, 3X vertical exaggeration Image: Landsat bands 1, 2&4, 3 as blue, green, and red, respectively Date Acquired: February 16, 2000 (SRTM), November 11, 1986 (Landsat) Image: NASA/JPL/NIMA

2000-01-01

24

Strait of Gibraltar, Perspective with Landsat Image Overlay  

NASA Technical Reports Server (NTRS)

This perspective view shows the Strait of Gibraltar, which is the entrance to the Mediterranean Sea from the Atlantic Ocean. Europe (Spain) is on the left. Africa (Morocco) is on the right. The Rock of Gibraltar, administered by Great Britain, is the peninsula in the back left.

The Strait of Gibraltar is the only natural gap in the topographic barriers that separate the Mediterranean Sea from the world's oceans. The Sea is about 3700 kilometers (2300 miles) long and covers about 2.5 million square kilometers (one million square miles), while the Strait is only about 13 kilometers (8 miles) wide. Sediment samples from the bottom of the Mediterranean Sea that include evaporite minerals, soils, and fossil plants show that about five million years ago the Strait was topographically blocked and the Sea had evaporated into a deep basin far lower in elevation than the oceans. Consequent changes in the world's hydrologic cycle, including effects upon ocean salinity, likely led to more ice formation in polar regions and more reflection of sunlight back to space, resulting in a cooler global climate at that time. Today, topography plays a key role in our regional climate patterns. But through Earth history, topographic change, even perhaps over areas as small as 13 kilometers across, has also affected the global climate.

This image was generated from a Landsat satellite image draped over an elevation model produced by the Shuttle Radar Topography Mission (SRTM). The view is eastward with a 3-times vertical exaggeration to enhance topographic expression. Natural colors of the scene (green vegetation, blue water, brown soil, white beaches) are enhanced by image processing, inclusion of some infrared reflectance (as green) to highlight the vegetation pattern, and inclusion of shading of the elevation model to further highlight the topographic features.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (99-feet) resolution of most Landsat images and will substantially help in analyses of the large Landsat image archive.

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC.

View Size: 46 kilometers (28 miles) wide, 106 kilometers (66 miles) distance Location: 36 degrees North latitude, 5.5 degrees West longitude Orientation: Looking East, 15 degrees down from horizontal, 3X vertical exaggeration Image Data: Landsat Bands 1, 2+4, 3 as blue, green, red respectively Original Data Resolution: 30 meters (99 feet) Date Acquired: February 2000 (SRTM), July 6, 1987 (Landsat)

2003-01-01

25

SRTM Perspective View with Landsat Overlay: Rann of Kachchh, India  

NASA Technical Reports Server (NTRS)

The earthquake that struck western India on January 26,2001, was the country's strongest in the past 50 years. This perspective view shows the area of the earthquake's epicenter in the lower left corner. The southern Rann of Kachchh appears in the foreground. The Rann is an area of low-lying salt flats that shows up with various shades of white and blue in this false-color Landsat image. The gray area on the middle of the image is called the Banni plains.

The darker blue spots and curving lines in the Rann and the Banni plains are features that appeared after the January earthquake. Their true colors are shades of white and gray, but the infrared data used in the image gives them a blue or turquoise color. These features are the effects of liquefaction of wet soil, sand and mud layers caused by the shaking of the earthquake. The liquefaction beneath the surface causes water to be squeezed out at the surface forming mud volcanoes, sand blows and temporary springs. Some of the residents of this dry area were hopeful that they could use the water, but they found that the water was too salty in almost every place where it came to the surface.

The city of Bhuj, India, appears as a gray area in the upper right of the image. Bhuj and many other towns and cities nearby were almost completely destroyed by the January 2001 earthquake. This magnitude 7.7 earthquake was the deadliest in the history of India with some 20,000 fatalities and over a million homes damaged or destroyed. The city of Bhuj was the historical capital of the Kachchh region. Highways and rivers appear as dark lines. Vegetation appears bright green in this false-color Landsat image.

The city of Anjar is in the dark gray area near the upper left of the image. Previously damaged by a magnitude 6.1 earthquake in 1956 that killed 152people, Anjar suffered again in the larger 2001 earthquake.

The red hills in the center of the image are the Has and Karo Hills, which reach up to 300 m (900 feet) elevation. Geologists are studying the folded red sandstone layers that form these hills to determine if they are related to the fault that broke in the 2001 earthquake.

This three-dimensional perspective view was generated using topographic data from the Shuttle Radar Topography Mission (SRTM) and an enhanced false-color Landsat 7 satellite image. Colors are from Landsat bands 5, 4, and 2 as red, green and blue, respectively. Topographic expression is exaggerated 5X.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive. The Landsat 7 Thematic Mapper image used here was provided to the SRTM by the United States Geological Survey, Earth Resources Observation Systems (EROS) Data Center, Sioux Falls, South Dakota.

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11,2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC.

Size: scale varies in this perspective image Location: 23.5 deg. North lat., 69.9 deg. East lon. Orientation: looking Southwest Image Data: Landsat Bands 5, 4, 3 as red, gr

2001-01-01

26

SRTM Perspective View with Landsat Overlay: Manhattan Island, New York  

NASA Technical Reports Server (NTRS)

In this image of Manhattan, the city's skyscrapers appear as ghostly white spikes. The green patch in the middle of the image is Central park. The Hudson River is visible on the upper left-hand side and the east River on the upper right. Although not designed to measure the heights of buildings, the radar used by the Shuttle Radar Topography Mission (SRTM) was so sensitive that it easily detected the Manhattan skyscrapers but could not distinguish individual structures.

The image was generated using topographic data from SRTM and enhanced true-color Landsat 5 satellite images. Topographic shading in the image was enhanced with false shading derived from the elevation model. Topographic expression is exaggerated 6X.

The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60-meters (about 200-feet)long, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC.

Size: scale varies in this perspective, Manhattan is about 3.5 km (2.2 miles) across. Location: 40.8 deg. North lat., 74 deg. West lon. Orientation: North toward the top Image Data: Landsat bands 1, 2, 3, and 4 Date Acquired: February 12, 2000 (SRTM)

2000-01-01

27

Mount Ararat, Turkey, Perspective with Landsat Image Overlay  

NASA Technical Reports Server (NTRS)

This perspective view shows Mount Ararat in easternmost Turkey, which has been the site of several searches for the remains of Noah's Ark. The main peak, known as Great Ararat, is the tallest peak in Turkey, rising to 5165 meters (16,945 feet). This southerly, near horizontal view additionally shows the distinctly conically shaped peak known as 'Little Ararat' on the left. Both peaks are volcanoes that are geologically young, but activity during historic times is uncertain.

This image was generated from a Landsat satellite image draped over an elevation model produced by the Shuttle Radar Topography Mission (SRTM). The view uses a 1.25-times vertical exaggeration to enhance topographic expression. Natural colors of the scene are enhanced by image processing, inclusion of some infrared reflectance (as green) to highlight the vegetation pattern, and inclusion of shading of the elevation model to further highlight the topographic features.

Volcanoes pose hazards for people, the most obvious being the threat of eruption. But other hazards are associated with volcanoes too. In 1840 an earthquake shook the Mount Ararat region, causing an unstable part of mountain's north slope to tumble into and destroy a village. Visualizations of satellite imagery when combined with elevation models can be used to reveal such hazards leading to disaster prevention through improved land use planning.

But the hazards of volcanoes are balanced in part by the benefits they provide. Over geologic time volcanic materials break down to form fertile soils. Cultivation of these soils has fostered and sustained civilizations, as has occurred in the Mount Ararat region. Likewise, tall volcanic peaks often catch precipitation, providing a water supply to those civilizations. Mount Ararat hosts an icefield and set of glaciers, as seen here in this late summer scene, that are part of this beneficial natural process

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Geospatial-Intelligence Agency (NGA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC.

View Size: 124 kilometers (77 miles) wide, 148 kilometers (92 miles) distance Location: 39.7 degrees North latitude, 44.3 degrees East longitude Orientation: Looking South, 2 degrees down from horizontal, 1.25X vertical exaggeration Image Data: Landsat Bands 1, 2+4, 3 as blue, green, red respectively Date Acquired: February 2000 (SRTM), August 31, 1989 (Landsat)

2004-01-01

28

Kamchatka Peninsula, Russia 3-D Perspective with Landsat Overlay  

NASA Technical Reports Server (NTRS)

This three-dimensional perspective view, looking up the Tigil River, shows the western side of the volcanically active Kamchatka Peninsula, Russia. The image shows that the Tigil River has eroded down from a higher and differing landscape and now flows through, rather than around the large green-colored bedrock ridge in the foreground. The older surface was likely composed of volcanic ash and debris from eruptions of nearby volcanoes. The green tones indicate that denser vegetation grows on south facing sunlit slopes at the northern latitudes. High resolution SRTM elevation data will be used by geologists to study how rivers shape the landscape, and by ecologists to study the influence of topography on ecosystems.

This image shows how data collected by the Shuttle Radar Topography Mission (SRTM) can be used to enhance other satellite images. Color and natural shading are provided by a Landsat 7 image acquired on January 31, 2000. Terrain perspective and shading were derived from SRTM elevation data acquired on February 12, 2000. Topography is exaggerated by about six times vertically. The United States Geological Survey's Earth Resources Observations Systems (EROS) DataCenter, Sioux Falls, South Dakota, provided the Landsat data.

The Shuttle Radar Topography Mission (SRTM), launched on February 11,2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission is designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, an additional C-band imaging antenna and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) and the German (DLR) and Italian (ASI) space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC.

Size: 71 km (44 miles) x 20 km (12 miles) Location: 57 deg. North lat., 159 deg. East lon. Orientation: Looking to the east Original Data Resolution: 30 meters (99 feet) Date Acquired: February 12, 2000

2000-01-01

29

Pasadena, California Perspective View with Aerial Photo and Landsat Overlay  

NASA Technical Reports Server (NTRS)

This perspective view shows the western part of the city of Pasadena, California, looking north towards the San Gabriel Mountains. Portions of the cities of Altadena and La Canada-Flintridge are also shown. The image was created from three datasets: the Shuttle Radar Topography Mission (SRTM) supplied the elevation data; Landsat data from November 11, 1986 provided the land surface color (not the sky) and U. S. Geological Survey digital aerial photography provides the image detail. The Rose Bowl, surrounded by a golf course, is the circular feature at the bottom center of the image. The Jet Propulsion Laboratory, is the cluster of large buildings north of the Rose Bowl at the base of the mountains. A large landfill, Scholl Canyon, is the smooth area in the lower left corner of the scene.

This image shows the power of combining data from different sources to create planning tools to study problems that affect large urban areas. In addition to the well-known earthquake hazards, Southern California is affected by a natural cycle of fire and mudflows. Wildfires strip the mountains of vegetation, increasing the hazards from flooding and mudflows for several years afterwards. Data such as shown on this image can be used to predict both how wildfires will spread over the terrain and also how mudflows will be channeled down the canyons.

For a full-resolution, annotated version of this image, please select Figure 1, below: [figure removed for brevity, see original site]

The Shuttle Radar Topography Mission (SRTM), launched on February 11,2000, uses the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. The mission is designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, an additional C-band imaging antenna and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) and the German (DLR) and Italian (ASI) space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC.

Size: 5.8 km (3.6 miles) x 10 km (6.2 miles) Location: 34.16 deg. North lat., 118.16 deg. West lon. Orientation: Looking North Original Data Resolution: SRTM, 30 meters; Landsat, 30 meters; Aerial Photo, 3 meters (no vertical exaggeration) Date Acquired: February 16, 2000

2000-01-01

30

Los Alamos Fires From Landsat 7  

NASA Technical Reports Server (NTRS)

On May 9, 2000, the Landsat 7 satellite acquired an image of the area around Los Alamos, New Mexico. The Landsat 7 satellite acquired this image from 427 miles in space through its sensor called the Enhanced Thematic Mapper Plus (ETM+). Evident within the imagery is a view of the ongoing Cerro Grande fire near the town of Los Alamos and the Los Alamos National Laboratory. Combining the high-resolution (30 meters per pixel in this scene) imaging capacity of ETM+ with its multi-spectral capabilities allows scientists to penetrate the smoke plume and see the structure of the fire on the surface. Notice the high-level of detail in the infrared image (bottom), in which burn scars are clearly distinguished from the hotter smoldering and flaming parts of the fire. Within this image pair several features are clearly visible, including the Cerro Grande fire and smoke plume, the town of Los Alamos, the Los Alamos National Laboratory and associated property, and Cerro Grande peak. Combining ETM+ channels 7, 4, and 2 (one visible and two infrared channels) results in a false color image where vegetation appears as bright to dark green (bottom image). Forested areas are generally dark green while herbaceous vegetation is light green. Rangeland or more open areas appear pink to light purple. Areas with extensive pavement or urban development appear light blue or white to purple. Less densely-developed residential areas appear light green and golf courses are very bright green. The areas recently burned appear black. Dark red to bright red patches, or linear features within the burned area, are the hottest and possibly actively burning areas of the fire. The fire is spreading downslope and the front of the fire is readily detectable about 2 kilometers to the west and south of Los Alamos. Combining ETM+ channels 3, 2, and 1 provides a true-color image of the greater Los Alamos region (top image). Vegetation is generally dark to medium green. Forested areas are very dark green while herbaceous vegetation is medium green. Rangeland or more open areas appear as tan or light brown. Areas with extensive pavement or urban development appear white to light green. Less densely-developed residential areas appear medium green and golf courses are medium green. The fires and areas recently burned are obscured by smoke plumes which are white to light blue. Landsat 7 data are archived and available from EDC. Image by Rob Simmon, Earth Observatory, NASA Goddard Space Flight Center. Data courtesy Randy McKinley, EROS Data Center (EDC)

2002-01-01

31

SRTM Perspective View with Landsat Overlay: Santa Monica Bay to Mount Baden-Powell, California  

NASA Technical Reports Server (NTRS)

Los Angeles may be the world's entertainment capital, but it is a difficult place to locate television and radio antennas. The metropolitan area spreads from the Pacific Ocean to Southern California's upper and lower deserts, valleys, mountains, canyons and coastal plains. While this unique geography offers something for everyone in terms of urban, suburban, small-town, and even semi-rural living, reception of television and radio signals can be problematic where there is no line-of-sight to a transmitting antenna. Broadcasters must choose antenna sites carefully in order to reach the greatest number of customers. Most local television towers are located atop Mount Wilson (elevation 1740 m =5710 ft), which is located on the front range of the San Gabriel Mountains (indistinctly visible, just right of the image center). This site is preferable to the highest peak seen here (Mount Baden-Powell, 2865 m =9399 ft) because it's closer to the urban center and has fewer obstructing peaks. It is also situated at a protruding bend in the mountain front and has few obstructions to the left and right. Computer automated methods combined with elevation models produced by SRTM will quantitatively optimize such factors in the siting of future transmission antenna installations worldwide.

This perspective view looks northeastward from the Santa Monica Bay. The San Fernando Valley is on the left, Pasadena is against the mountain front at right-center, and downtown Los Angeles is on the coastal plain directly in front of Mount Baden-Powell. This image was generated by draping a Landsat satellite image over a preliminary topographic map from the Shuttle Radar Topography Mission (SRTM). Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive.

The elevation data used in this image was acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on February 11,2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise,Washington, DC.

Size: 29 kilometers (18 miles) view width, 70 kilometers (43 miles) view distance Location: 34.2 deg. North lat., 118.2 deg. West lon. Orientation: View toward the northeast, 3X vertical exaggeration Image: Landsat bands 1, 2&4, 3 as blue, green, and red, respectively Date Acquired: February 16, 2000 (SRTM), November 11, 1986 (Landsat)

2000-01-01

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Digital overlaying of the Universal Transverse Mercator Grid with LANDSAT-data derived products  

NASA Technical Reports Server (NTRS)

Software has been written in FORTRAN IV for a Varian 73 computer which reformats LANDSAT-data-derived surface classifications and pictorial representations into a digital array which corresponds to the Universal Transverse Mercator Grid.

Pendleton, T. W.

1976-01-01

33

SRTM Stereo Pair with Landsat Overlay: Miquelon and Saint Pierre Islands  

NASA Technical Reports Server (NTRS)

This stereoscopic satellite image shows Miquelon and Saint Pierre Islands, located south of Newfoundland, Canada. These islands are a self-governing territory of France. A 'tombolo' (sand bar) unites Grande Miquelon to the north and Petite Miquelon to the south. Saint Pierre Island, located to the lower right, includes a harbor, an airport, and a small town. Glaciers once covered these islands and the direction of glacial flow is evident in the topography as striations and shoreline trends running from the upper right to the lower left. The darkest image features are freshwater lakes that fill glacially carved depressions and saltwater lagoons that are bordered by barrier beaches. The lakes and the lagoons are fairly calm waters and reflect less sunlight than do the wave covered and sediment laden nearshore ocean currents.

This stereoscopic image was generated by draping a Landsat satellite image over a preliminary Shuttle Radar Topography Mission (SRTM)elevation model. Two differing perspectives were then calculated, one for each eye. They can be seen in 3-D by viewing the left image with the right eye and the right image with the left eye (cross-eyed viewing), or by downloading and printing the image pair and viewing them with a stereoscope. When stereoscopically merged, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive. The Landsat 7 Thematic Mapper image used here was provided to the SRTM project by the United States Geological Survey, Earth Resources Observation Systems (EROS) DataCenter, Sioux Falls, South Dakota.

The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60-meters (about 200-feet)long, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington DC.

Size: 48 by 38 kilometers (30 by 24 miles) Location: 47 deg. North lat., 56.3 deg. West lon. Orientation: North toward the upper left Image Data: Landsat bands 1, 2+4, 3 in blue, green, red, respectively Date Acquired: February 12, 2000 (SRTM), September 1, 1999 (Landsat) Image: NASA/JPL/NIMA

2000-01-01

34

Perspective View with Landsat Overlay, Salt Lake City Olympics Venues, Utah  

NASA Technical Reports Server (NTRS)

The 2002 Winter Olympics are hosted by Salt Lake City at several venues within the city, in nearby cities, and within the adjacent Wasatch Mountains. This computer generated perspective image provides a northward looking 'view from space' that includes all of these Olympic sites. In the south, next to Utah Lake, Provo hosts the ice hockey competition. In the north, northeast of the Great Salt Lake, Ogden hosts curling, and the nearby Snow Basin ski area hosts the downhill events. In between, southeast of the Great Salt Lake, Salt Lake City hosts the Olympic Village and the various skating events. Further east, across the Wasatch Mountains, the Park City area ski resorts host the bobsled, ski jumping, and snowboarding events. The Winter Olympics are always hosted in mountainous terrain. This view shows the dramatic landscape that makes the Salt Lake City region a world-class center for winter sports.

This 3-D perspective view was generated using topographic data from the Shuttle Radar Topography Mission (SRTM) and a Landsat 5 satellite image mosaic. Topographic expression is exaggerated four times.

For a full-resolution, annotated version of this image, please select Figure 1, below: [figure removed for brevity, see original site]

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and will substantially help in analyzing the large and growing Landsat image archive, managed by the U.S. Geological Survey (USGS).

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter(approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C.

Size: View width 48.8 kilometers (30.2 miles), View distance 177 kilometers (110 miles) Location: 41 deg. North lat., 112.0 deg. West lon. Orientation: View North, 20 degrees below horizontal Image Data: Landsat Bands 3, 2, 1 as red, green, blue, respectively. Original Data Resolution: SRTM 1 arcsecond (30 meters or 98 feet), Thematic Mapper 30 meters (98 feet) Date Acquired: February 2000 (SRTM), 1990s (Landsat 5 image mosaic)

2002-01-01

35

SRTM Perspective View with Landsat Overlay: Caliente Range and Cuyama Valley, California  

NASA Technical Reports Server (NTRS)

Before the arrival of Europeans, California's Cuyama Valley was inhabited by Native Americans who were culturally and politically tied to the Chumash tribes of coastal Santa Barbara County. Centuries later, the area remains the site of noted Native American rock art paintings. In the 1800s, when Europeans established large cattle and horse-breeding ranches in the valley, the early settlers reported the presence of small villages along the Cuyama River. This perspective view looks upstream toward the southeast through the Cuyama Valley. The Caliente Range, with maximum elevations of 1,550 meters (5,085 feet), borders the valley on the left. The Cuyama River, seen as a bright meandering line on the valley floor, enters the valley from headwaters more than 2,438 meters (8,000 feet) above sea level near Mount Abel and flows 154 kilometers (96 miles) before emptying into the Pacific Ocean. The river's course has been determined in large part by displacement along numerous faults.

Today, the Cuyama Valley is the home of large ranches and small farms. The area has a population of 1,120 and is more than an hour and a half drive from the nearest city in the county.

This image was generated by draping an enhanced Landsat satellite image over elevation data from the Shuttle Radar Topography Mission (SRTM). Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter resolution of most Landsat images and will substantially help in analyses of the large and growing Landsat image archive. For visualization purposes, topographic heights displayed in this image are exaggerated two times. Colors approximate natural colors.

The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60 meters (about 200 feet)long, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif, for NASA's Earth Science Enterprise, Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena.

Location (Center): 34.97 deg. North lat., 119.70 deg. West lon. View: Southeast Scale: Scale Varies in this Perspective Date Acquired: February 16, 2000 SRTM, December 14, 1984 Landsat

2001-01-01

36

SRTM Perspective View with Landsat Overlay: Syracuse, Oneida Lake, Upstate New York  

NASA Technical Reports Server (NTRS)

In the lower center of this perspective view of upstate New York, the city of Syracuse hugs the southeastern banks (top right side) of Lake Onondaga, the smaller of the two dark features that dominate the scene. The view is toward the east. The urban area appears bright in stark contrast to the dark waterways and the greens, browns and yellows of the vegetated areas. Both of the two black features are lakes. Oneida Lake , the larger of the two is to the left of the scene center. About 1/3 of the way between Lakes Onondaga and Oneida are the triangular shaped runways of the Syracuse Hancock International Airport. The Adirondack Mountains are to the upper left while the less rugged Catskills can be seen in the upper right. A faint outline of the Mohawk River can be seen as threads its way down from the Adirondacks toward the city of Rome, the bright area in the valley between the lake and the Adirondacks. The Erie Canal and the Oswego River are part of the network of waterways seen in the left image foreground.

Fall foliage in a variety of colors can be seen in the Landsat data used here. Redder vegetation generally occurs at higher elevations and toward the north (left), especially in the Adirondack Mountains. The back edge of the data set forms a false skyline. The image was generated using topographic data from SRTM and enhanced true-color Landsat 5 satellite images. Topographic shading in the image was enhanced with false shading derived from the elevation model. Topographic expression is exaggerated 6X. Syracuse lies at the geographic center of the state of New York and has been the site of its state fair for most of that event's 154 years. It is located in an agricultural and resort area. The yellowish rectangular features in the foreground of the image are farmlands. Parts of Skaneateles and Otisco Lakes, some of central New York's Finger Lakes, can be seen in the bottom right corner of the image.

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the National Aeronautics and Space Administration (NASA), the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense (DoD), and the German and Italian Space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Earth Science Enterprise, Washington, DC.

Size: 200 kilometers View Distance x 280 kilometers View Width (Background) (125 by 175 miles) Location: 43.1 deg. North Lat, 76.1.deg. West Lon. (Syracuse) Orientation: View is toward the east Date Acquired: SRTM, February 13, 2000; Landsat, various

2000-01-01

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SRTM Perspective View with Landsat Overlay: Mt. Pinos and San Joaquin Valley, California  

NASA Technical Reports Server (NTRS)

Ask any astronomer where the best stargazing site in Southern California is, and chances are they'll say Mt. Pinos. In this perspective view generated from SRTM elevation data the snow-capped peak is seen rising to an elevation of 2,692 meters (8,831 feet), in stark contrast to the flat agricultural fields of the San Joaquin valley seen in the foreground. Below the summit, but still well away from city lights, the Mt. Pinos parking lot at 2,468 meters (8,100 feet) is a popular viewing area for both amateur and professional astronomers and astro-photographers. For visualization purposes, topographic heights displayed in this image are exaggerated two times.

The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60 meters (about 200 feet)long, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise,Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena.

Distance to Horizon: 176 kilometers (109 miles) Location: 34.83 deg. North lat., 119.25 deg. West lon. View: Toward the Southwest Date Acquired: February 16, 2000 SRTM, December 14, 1984 Landsat

2000-01-01

38

SRTM Perspective View with Landsat Overlay: Ventura, and Lake Casitas, California  

NASA Technical Reports Server (NTRS)

Ventura, California is one of this state's oldest cities. Officially known as San Buenaventura, it was established in 1782 with the founding of the Mission San Buenaventura, the ninth of the 21 Spanish missions founded in California. In this perspective view generated from SRTM elevation data, the city can be seen occupying the shore of the Pacific Ocean and the nearby foothills. Lake Casitas, a reservoir and popular recreation area, is the dark blue feature in the center of the image. Holding back the 313,000 megaliter (254,000 acre-feet) storage capacity of the reservoir and visible as a very bright feature foreground of the lake, is the Casitas Dam, a 102-meter(334-foot) Earth fill dam. The reservoir and dam were built between 1956 and 1959 for the Federal Bureau of Reclamation's Ventura River Project. In addition to recreational use, Lake Casitas provides irrigation, municipal and industrial water to urban and suburban areas in Ventura County. For visualization purposes, topographic heights displayed in this image are exaggerated two times.

The elevation data used in this image was acquired by SRTM aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on Endeavour in 1994. SRTM was designed to collect three-dimensional measurements of Earth's land surface. To collect the 3-D SRTM data, engineers added a mast 60 meters (about 200 feet)long, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between the NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise,Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena.

Distance to Horizon: 54.5 kilometers (33.8 miles) Location: 34.38 deg. North lat., 119.3 deg. West lon. View: Toward the North Date Acquired: February 16, 2000 SRTM, December 14, 1984 Landsat

2000-01-01

39

The use of radar and LANDSAT data for mineral and petroleum exploration in the Los Andes region, Venezuela  

NASA Technical Reports Server (NTRS)

A geological study of a 27,500 sq km area in the Los Andes region of northwestern Venezuela was performed which employed both X-band radar mosaics and computer processed Landsat images. The 3.12 cm wavelength radar data were collected with horizontal-horizontal polarization and 10 meter spatial resolution by an Aeroservices SAR system at an altitude of 12,000 meters. The radar images increased the number of observable suspected fractures by 27 percent over what could be mapped by LANDSAT alone, owing mostly to the cloud cover penetration capabilities of radar. The approximate eight fold greater spatial resolution of the radar images made possible the identification of shorter, narrower fractures than could be detected with LANDSAT data alone, resulting in the discovery of a low relief anticline that could not be observed in LANDSAT data. Exploration targets for petroleum, copper, and uranium were identified for further geophysical work.

Vincent, R. K.

1980-01-01

40

Landsat: Space Activities for Students  

ERIC Educational Resources Information Center

An aerospace education activity is described which is suitable for grades 3-12. Students piece together several images from the Landsat satellite to make a mosaic of their state. From the mosaic clear acetate overlay maps can be made relating to such subjects as agriculture, geology, hydrology, or urban planning. (BB)

Marks, Steven K.

1979-01-01

41

Flexolith Overlay.  

National Technical Information Service (NTIS)

The report describes the installation and post-construction evaluation of a thin, lightweight epoxy concrete bridge deck overlay. The subject 'Flexolith' epoxy concrete system was installed by Dural International Corporation on a bridge located on I-82 ne...

K. W. Anderson

1987-01-01

42

An Automatic Overlay Generator  

Microsoft Academic Search

We present an algorithm for automatically generating an overlay structure for a program, with the goal of reducing the primary storage requirements of that program. Subject to the constraints of intermodule dependences, the algorithm can either find a maximal overlay structure or find an overlay structure that, where possible, restricts the program to a specified amount of primary storage. Results

Ron Cytron; Paul G. Loewner

1986-01-01

43

Landsat Activity  

NSDL National Science Digital Library

This activity involves the use of satellite imagery to derive observations. Using an introductory Landsat classroom activity, learners will compare two images from North Dakota to quantify how much of the land surface that was water in 1997 has been changed to land by 2007. A link to the introductory activity is provided. This is the third of three activities in the "The Impact of Climate Change on Prairie Potholes" section of the "Climate Change, Wildlife and Wildlands: A Toolkit for Formal and Informal Educators."

44

Computer mapping of LANDSAT data for environmental applications  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. Land cover overlays and maps produced from LANDSAT are providing information on existing land use and resources throughout the 208 study area. The overlays are being used to delineate drainage areas of a predominant land cover type. Information on cover type is also being combined with other pertinent data to develop estimates of sediment and nutrients flows from the drainage area. The LANDSAT inventory of present land cover together with population projects is providing a basis for developing maps of anticipated land use patterns required to evaluate impact on water quality which may result from these patterns. Overlays of forest types were useful for defining wildlife habitat and vegetational resources in the region. LANDSAT data and computer assisted interpretation was found to be a rapid cost effective procedure for inventorying land cover on a regional basis. The entire 208 inventory which include acquisition of ground truth, LANDSAT tapes, computer processing, and production of overlays and coded tapes was completed within a period of 2 months at a cost of about 0.6 cents per acre, a significant improvement in time and cost over conventional photointerpretation and mapping techniques.

Rogers, R. H. (principal investigator); Mckeon, J. B.; Reed, L. E.; Schmidt, N. F.; Schecter, R. N.

1975-01-01

45

Properties of martensitic overlays  

Microsoft Academic Search

The abrasive wear resistance of martensitic overlays is the function of many variables. The hardness is one of the variables. This fact is raised by the possibility of carbidic phases separating from the austenite in the course the overlay layer cooling and by the possibility of the further martensite disintegration and carbidic phases precipitation. The paper is engaged in the

R. Chot?borský; M. Müller

46

LANDSAT-1 and LANDSAT-2 flight evaluation  

NASA Technical Reports Server (NTRS)

Flight performances of LANDSAT 1 and LANDSAT 2 are evaluated. The in-flight systems discussed are: (1) power supplies, (2) attitude control, (3) command/clock, (4) telemetry, (5) orbit adjust, (6) electrical interface, (7) thermal, (8) tape recorders, (9) multispectral scanner, (10) data collection and (11) magnetic moment compensating assembly. Tables are presented for easy reference.

1976-01-01

47

Landsat-1 and Landsat-2 flight evaluation  

NASA Technical Reports Server (NTRS)

The flight performance of Landsat 1 and Landsat 2 is analyzed. Flight operations of the satellites are briefly summarized. Other topics discussed include: orbital parameters; power subsystem; attitude control subsystem; command/clock subsystem; telemetry subsystem; orbit adjust subsystem; magnetic moment compensating assembly; unified s-band/premodulation processor; electrical interface subsystem; thermal subsystem; narrowband tape recorders; wideband telemetry subsystem; attitude measurement sensor; wideband video tape recorders; return beam vidicon; multispectral scanner subsystem; and data collection subsystem.

1975-01-01

48

Embeddable Overlay Networks  

Microsoft Academic Search

Internet round-trip-times (RTTs) exhibit widespread and persistent Triangle Inequality Violations (TIVs). It has been shown that TIVs are a natural consequence of the Internet's routing structure and they degrade the embedding accuracy of any Internet coordinate systems based on RTTs. In this paper, we simulate a coordinate system in a hypothetical overlay environment where RTTs are measured with respect to

Eng Keong Lua; Timothy G. Griffin

2007-01-01

49

Methodology for overlay mark selection  

Microsoft Academic Search

It is known that different overlay mark designs will have different responses to process setup conditions. An overlay mark optimized for the 45nm technology node might not be suitable for wafers using 30nm or 20nm process technologies due to changes in lithography and process conditions. As overlay control specifications become tighter and tighter, the process engineer requires metrics beyond precision,

Chin-Chou Kevin Huang; Chao-Tien Healthy Huang; Anna Golotsvan; David Tien; Chui-Fu Chiu; Chun-Yen Huang; Wen-Bin Wu; Chiang-Lin Shih

2011-01-01

50

Methodology for overlay mark selection  

NASA Astrophysics Data System (ADS)

It is known that different overlay mark designs will have different responses to process setup conditions. An overlay mark optimized for the 45nm technology node might not be suitable for wafers using 30nm or 20nm process technologies due to changes in lithography and process conditions. As overlay control specifications become tighter and tighter, the process engineer requires metrics beyond precision, tool-induced shift (TIS) and TIS variability to determine the optimal target design. In this paper, the authors demonstrate a novel, comprehensive methodology which employs source of variance (SOV) to help engineers select the best overlay marks to meet overlay control requirements.

Huang, Chin-Chou Kevin; Huang, Chao-Tien Healthy; Golotsvan, Anna; Tien, David; Chiu, Chui-Fu; Huang, Chun-Yen; Wu, Wen-Bin; Shih, Chiang-Lin

2011-03-01

51

LandsatLook images  

USGS Publications Warehouse

LandsatLook images are full resolution JPEG files derived from Landsat Level 1 data products. The images are compressed and stretched to create an image optimized for image selection and visual interpretation; it is not recommended that they be used in digital analysis.

Jonescheit, Linda

2011-01-01

52

The overlay performance optimization based on overlay manager system  

NASA Astrophysics Data System (ADS)

Based on the in-line metrology sampling and modeling, the Advanced Process Control (APC) system has been widely used to control the combined effects of process errors. With the shrinking of overlay budgets, the automated optimized overlay management system has already been necessary. To further improve the overlay performance of SMEE SSA600/10A exposure system, the overlay manager system (OMS) is introduced. The Unilith software package developed by SMEE included in the OMS is used for the decomposition and analysis of sampled data. Several kinds of correction methods integrated in the OMS have been designed and have demonstrated effective results in automated overlay control. To balance the overlay performance and the metrology time, the exponential weighting method for sampling is also considered.

Sun, G.; Zhu, J.; Li, S. X.; Mao, F. L.; Duan, L. F.

2012-03-01

53

Electrically conductive polymer concrete overlays  

NASA Astrophysics Data System (ADS)

The use of cathodic protection to prevent the corrosion of reinforcing steel in concrete structures has been well established. Application of a durable, skid-resistant electrically conductive polymer concrete overlay would advance the use of cathodic protection for the highway industry. Laboratory studies indicate that electrically conductive polymer concrete overlays using conductive fillers, such as calcined coke breeze, in conjunction with polyester or vinyl ester resins have resistivities of 1 to 10 ohm-cm. Both multiple-layer and premixed mortar-type overlays were made. Shear bond strengths of the conductive overlays to concrete substrates vary from 600 to 1300 psi, with the premixed overlays having bond strengths 50 to 100% higher than the multiple-layer overlays.

Fontana, J. J.; Webster, R. P.

1984-08-01

54

Landsat Earth Monitor.  

ERIC Educational Resources Information Center

The uses of NASA's Landsat in the areas of cartography, flood control, agricultural inventory, land use mapping, water runoff, urban planning, erosion, geology, and water quality monitoring are illustrated. (BB)

Haggerty, James J.

1979-01-01

55

LANDSAT data preprocessing  

NASA Technical Reports Server (NTRS)

The effect on LANDSAT data of a Sun angle correction, an intersatellite LANDSAT-2 and LANDSAT-3 data range adjustment, and the atmospheric correction algorithm was evaluated. Fourteen 1978 crop year LACIE sites were used as the site data set. The preprocessing techniques were applied to multispectral scanner channel data and transformed data were plotted and used to analyze the effectiveness of the preprocessing techniques. Ratio transformations effectively reduce the need for preprocessing techniques to be applied directly to the data. Subtractive transformations are more sensitive to Sun angle and atmospheric corrections than ratios. Preprocessing techniques, other than those applied at the Goddard Space Flight Center, should only be applied as an option of the user. While performed on LANDSAT data the study results are also applicable to meteorological satellite data.

Austin, W. W.

1983-01-01

56

Landsat's international partners  

USGS Publications Warehouse

Since the launch of the first Landsat satellite 40 years ago, International Cooperators (ICs) have formed a key strategic alliance with the U.S. Geological Survey (USGS) to not only engage in Landsat data downlink services but also to enable a foundation for scientific and technical collaboration. The map below shows the locations of all ground stations operated by the United States and IC ground station network for the direct downlink and distribution of Landsat 5 (L5) and Landsat 7 (L7) image data. The circles show the approximate area over which each station has the capability for direct reception of Landsat data. The red circles show the components of the L5 ground station network, the green circles show components of the L7 station network, and the dashed circles show stations with dual (L5 and L7) status. The yellow circles show L5 short-term ("campaign") stations that contribute to the USGS Landsat archive. Ground stations in South Dakota and Australia currently serve as the primary data capture facilities for the USGS Landsat Ground Network (LGN). The Landsat Ground Station (LGS) is located at the USGS Earth Resources Observation and Science (EROS) Center in Sioux Falls, South Dakota. The Alice Springs (ASN) ground station is located at the Geoscience Australia facility in Alice Springs, Australia. These sites receive the image data, via X-band Radio Frequency (RF) link, and the spacecraft housekeeping data, via S-band RF link. LGS also provides tracking services and a command link to the spacecrafts.

Byrnes, Raymond A.

2012-01-01

57

Distributed Semantic Overlay Networks  

NASA Astrophysics Data System (ADS)

Semantic Overlay Networks (SONs) have been recently proposed as a way to organize content in peer-to-peer (P2P) networks. The main objective is to discover peers with similar content and then form thematically focused peer groups. Efficient content retrieval can be performed by having queries selectively forwarded only to relevant groups of peers to the query. As a result, less peers need to be contacted, in order to answer a query. In this context, the challenge is to generate SONs in a decentralized and distributed manner, as the centralized assembly of global information is not feasible. Different approaches for exploiting the generated SONs for content retrieval have been proposed in the literature, which are examined in this chapter, with a particular focus on SON interconnections for efficient search. Several applications, such as P2P document and image retrieval, can be deployed over generated SONs, motivating the need for distributed and truly scalable SON creation. Therefore, recently several research papers focus on SONs as stated in our comprehensive overview of related work in the field of semantic overlay networks. A classification of existing algorithms according to a set of qualitative criteria is also provided. In spite of the rich existing work in the field of SONs, several challenges have not been efficiently addressed yet, therefore, future promising research directions are pointed out and discussed at the end of this chapter.

Doulkeridis, Christos; Vlachou, Akrivi; Nørvåg, Kjetil; Vazirgiannis, Michalis

58

Landsat Radiometry Project  

NASA Technical Reports Server (NTRS)

This final report summarizes three years of work characterizing the radiometry of the Landsat 4, 5 and 7 Thematic Mappers. It is divided into six sections that are representative of the major areas of effort: 1) Internal Calibrator Lamp Monitoring; 2) Vicarious Calibration; 3) Relative Gain Analysis; 4) Outgassing; 5) Landsat 4 Absolute Calibration; and 6) Landsat 5 Scene Invariant Analysis. Each section provides a summary overview of the work that has been performed at SDSU. Major results are highlighted. In several cases, references are given to publications that have developed from this work, Several team members contributed to this report: Tim Ruggles, Dave Aaron, Shriharsha Madhavan, Esad Micijevic, Cory Mettler, and Jim Dewald. At the end of the report is a summary section.

2005-01-01

59

Electrically Conductive Polymer Concrete Overlays.  

National Technical Information Service (NTIS)

The use of cathodic protection to prevent the corrosion of reinforcing steel in concrete structures has been well established. Application of a durable, skid-resistant electrically conductive polymer concrete overlay would advance the use of cathodic prot...

J. J. Fontana R. P. Webster

1984-01-01

60

Electrically Conductive Polymer Concrete Overlays.  

National Technical Information Service (NTIS)

The development of a built-up, electrically conductive polymer concrete overlay and a premixed, electrically conductive polymer concrete mortar for use on bridge decks and other concrete members, in conjunction with cathodic protection systems, is reporte...

R. P. Webster J. J. Fontana W. Reams

1985-01-01

61

Reliable Communication in Overlay Networks  

Microsoft Academic Search

Reliable point-to-point communication is usually achieved in overlay networks by applying TCP on the end nodes of a connection. This paper presents a hop-by-hop reliability approach that considerably reduces the latency and jitter of reliable connections. Our approach is feasible and beneficial in overlay networks that do not have the scalability and interoperability requirements of the global Internet. The effects

Yair Amir; Claudiu Danilov

2003-01-01

62

Quayle saves Landsat program  

NASA Astrophysics Data System (ADS)

With a last-minute budget reprieve from the Bush administration, Landsats 4 and 5, the sole public U.S. source of detailed satellite images of Earth, have another six months of life. The impending shutoff of the satellites on March 31 without an infusion of funds has focused attention on the public—private partnership that manages the Landsat program.EOSAT , Inc., the private corporation that operates Landsats 4 and 5, needs $9.4 million to maintain the satellites until the end of the fiscal year in October. As it has in previous years, t h e Reagan administration included no money in its FY 1989 budget to keep the spacecraft working, a n d the Bush administration has not amended that policy. Congress has restored operating funds in the past, but this time it was the National Space Council, headed by Vice President Dan Quayle, that released a statement saying that federal agencies that are many of the biggest customers for remote sensing data from the satellites will pay at least some of the costs. Under the plan the rest would be supplied by EOSAT, which markets Landsat data.

Maggs, William Ward

63

Landsat: Mt. Redoubt  

USGS Multimedia Gallery

Landsat 5 image of the Mt. Redoubt area on March 26, 2009 at 1:07 PM AKDT. The false color image shows the large brown ash cloud extending over the Cook Inlet and the western Kenai peninsula (right sid of image). The image also shows a whiter steam and gas plume rising from the summit of Redoubt Vol...

2009-04-06

64

LANDSAT information for state planning  

NASA Technical Reports Server (NTRS)

The transfer of remote sensing technology for the digital processing of LANDSAT data to state and local agencies in Georgia and other southeastern states is discussed. The project consists of a series of workshops, seminars, and demonstration efforts, and transfer of NASA-developed hardware concepts and computer software to state agencies. Throughout the multi-year effort, digital processing techniques have been emphasized classification algorithms. Software for LANDSAT data rectification and processing have been developed and/or transferred. A hardware system is available at EES (engineering experiment station) to allow user interactive processing of LANDSAT data. Seminars and workshops emphasize the digital approach to LANDSAT data utilization and the system improvements scheduled for LANDSATs C and D. Results of the project indicate a substantially increased awareness of the utility of digital LANDSAT processing techniques among the agencies contracted throughout the southeast. In Georgia, several agencies have jointly funded a program to map the entire state using digitally processed LANDSAT data.

Faust, N. L.; Spann, G. W.

1977-01-01

65

Photointerpretation of LANDSAT images  

NASA Technical Reports Server (NTRS)

Learning objectives include: (1) developing a facility for applying conventional techniques of photointerpretation to small scale (satellite) imager; (2) promoting the ability to locate, identify, and interpret small natural and man made surface features in a LANDSAT image; (3) using supporting imagery, such as aerial and space photography, to conduct specific applications analyses; (4) learning to apply change detection techniques to recognize and explain transient and temporal events in individual or seasonal imagery; (5) producing photointerpretation maps that define major surface units, themes, or classes; (6) classifying or analyzing a scene for specific discipline applications in geology, agriculture, forestry, hyrology, coastal wetlands, and environmental pollution; and (7) evaluating both advantages and shortcomings in relying on the photointerpretive approach (rather than computer based analytical approach) for extracting information from LANDSAT data.

1982-01-01

66

Landsat US standard catalog  

NASA Technical Reports Server (NTRS)

The U.S. Standard Catalog lists imagery of the continental U.S., Alaska and Hawaii acquired by Landsat 1 and 2 which has been processed and input to the data files during the referenced month. Data, such as date acquired, cloud cover and image quality are given for each scene. The microfilm roll and frame on which the scene may be found is also given.

1975-01-01

67

Overlay welding irradiated stainless steel  

NASA Astrophysics Data System (ADS)

An overlay technique developed for welding irradiated stainless steel may be important for repair or modification of fusion reactor materials. Helium, present due to (n,alpha) reactions, is known to cause cracking using conventional welding methods. Stainless steel impregnated with 3 to 220 appm helium by decay of tritium was used to develop a welding process that could be used for repair. The result was a gas metal arc weld overlay technique with low-heat input and low-penetration into the helium-containing material. Extensive metallurgical and mechanical testing of this technique demonstrated substantial reduction of helium embrittlement damage. The overlay technique was applied to irradiated 304 stainless steel containing 10 appm helium. Surface cracking, present in conventional welds made on the same steel at lower helium concentrations, was eliminated. Underbead cracking, although greater than for tritium charged and aged material, was minimal compared to conventional welding methods.

Kanne, W. R.; Chandler, G. T.; Nelson, D. Z.; Franco-Ferreira, E. A.

68

Landsat data commercialized  

NASA Astrophysics Data System (ADS)

Data for about 600,000 Landsat scenes—all those acquired by multispectral scanners (MSS) aboard Landsat satellites more than 2 years ago—are now available from the Earth Resources Observation Systems (EROS) Data Center (EDC) in Sioux Falls, S. Dak., at reduced prices. Landsat images are valuable for planning, change detection, and monitoring of Earth resources and environment and provide unique information about land conditions and changes during the 1970s and 1980s that is not available from other sources. The availability of the data are expected to benefit substantially the study of global climate change as an early indicator of climate change and as a contributor to changes in the chemical composition of the atmosphere. An agreement was recently signed between the National Oceanic and Atmospheric Administration and the Earth Observation Satellite, whereby MSS data more than 2 years old will be distributed through both EOSAT and the U.S. Geological Survey. EOSAT retains exclusive sales rights to MSS data less than 2 years old.

69

Landsat 6 contract signed  

NASA Astrophysics Data System (ADS)

A new agreement provides $220 million for development and construction of the Landsat 6 remote sensing satellite and its ground systems. The contract, signed on March 31, 1988, by the Department of Commerce (DOC) and the Earth Observation Satellite (EOSAT) Company of Lanham, Md., came just days after approval of DOC's Landsat commercialization plan by subcommittees of the House and Senate appropriations committees.The Landsat 6 spacecraft is due to be launched into orbit on a Titan II rocket in June 1991 from Vandenburg Air Force Base, Calif. The satellite will carry an Enhanced Thematic Mapper (ETM) sensor, an instrument sensitive to electromagnetic radiation in seven ranges or bands of wavelengths. The satellite's payload will also include the Sea Wide Field Sensor (Sea-WiFS), designed to provide information on sea surface temperature and ocean color. The sensor is being developed in a cooperative effort by EOSAT and the National Aeronautics and Space Administration (NASA). A less certain passenger is a proposed 5-m resolution, three-band sensor sensitive to visible light. EOSAT is trying to find both private financing for the device and potential buyers of the high-resolution imagery that it could produce. The company has been actively courting U.S. television networks, which have in the past used imagery from the European Système Probatoire d'Observation de la Terre (SPOT) satellite for news coverage.

Maggs, William Ward

70

New analytical algorithm for overlay accuracy  

NASA Astrophysics Data System (ADS)

The extension of optical lithography to 2Xnm and beyond is often challenged by overlay control. With reduced overlay measurement error budget in the sub-nm range, conventional Total Measurement Uncertainty (TMU) data is no longer sufficient. Also there is no sufficient criterion in overlay accuracy. In recent years, numerous authors have reported new method of the accuracy of the overlay metrology: Through focus and through color. Still quantifying uncertainty in overlay measurement is most difficult work in overlay metrology. According to the ITRS roadmap, total overlay budget is getting tighter than former device node as a design rule shrink on each device node. Conventionally, the total overlay budget is defined as the square root of square sum of the following contributions: the scanner overlay performance, wafer process, metrology and mask registration. All components have been supplying sufficiently performance tool to each device nodes, delivering new scanner, new metrology tools, and new mask e-beam writers. Especially the scanner overlay performance was drastically decreased from 9nm in 8x node to 2.5nm in 3x node. The scanner overlay seems to reach the limitation the overlay performance after 3x nod. The importance of the wafer process overlay as a contribution of total wafer overlay became more important. In fact, the wafer process overlay was decreased by 3nm between DRAM 8x node and DRAM 3x node. We develop an analytical algorithm for overlay accuracy. And a concept of nondestructive method is proposed in this paper. For on product layer we discovered the layer has overlay inaccuracy. Also we use find out source of the overlay error though the new technique. In this paper, authors suggest an analytical algorithm for overlay accuracy. And a concept of non-destructive method is proposed in this paper. For on product layers, we discovered it has overlay inaccuracy. Also we use find out source of the overlay error though the new technique. Furthermore total overlay error data is decomposed into two parts: the systematic error and the random error. And we tried to show both error components characteristic, systematic error has a good correlation with residual error by scanner condition, whereas, random error has a good correlation with residual error as going process steps. Furthermore, we demonstrate the practical using case with proposed method that shows the working of the high order method through systematic error. Our results show that to characterize an overlay data that is suitable for use in advanced technology nodes requires much more than just evaluating the conventional metrology metrics of TIS and TMU.

Ham, Boo-Hyun; Yun, Sangho; Kwak, Min-Cheol; Ha, Soon Mok; Kim, Cheol-Hong; Nam, Suk-Woo

2012-03-01

71

Landsat 7 Science Data Processing: An Overview.  

National Technical Information Service (NTIS)

The Landsat 7 Science Data Processing System, developed by NASA for the Landsat 7 Project, provides the science data handling infrastructure used at the Earth Resources Observation Systems (EROS) Data Center (EDC) Landsat Data Handling Facility (DHF) of t...

R. J. Schweiss N. E. Daniel D. K. Derrick

2000-01-01

72

32nm overlay improvement capabilities  

NASA Astrophysics Data System (ADS)

The industry is facing a major challenge looking forward on the technology roadmap with respect to overlay control. Immersion lithography has established itself as the POR for 45nm and for the next few nodes. As the gap closes between scanner capability and device requirements new methodologies need to be taken into consideration. Double patterning lithography is an approach that's being considered for 32 and below, but it creates very strict demands for overlay performance. The fact that a single layer device will need to be patterned using two sequential single processes creates a strong coupling between the 1st and 2nd exposure. The coupling effect during the double patterning process results in extremely tight tolerances for overlay error and scanner capabilities. The purpose of this paper is to explore a new modeling method to improve lithography performance for the 32nm node. Not necessarily unique for double patterning, but as a general approach to improve overlay performance regardless of which patterning process is implemented. We will achieve this by performing an in depth source of variance analysis of current scanner performance and project the anticipated improvements from our new modeling approach. Since the new modeling approach will involve 2nd and 3rd order corrections we will also provide and analysis that outlines current metrology capabilities and sampling optimizations to further expand the opportunities of an efficient implementation of such approach.

Eichelberger, Brad; Huang, Kevin; O'Brien, Kelly; Tien, David; Tsai, Frank; Minvielle, Anna; Singh, Lovejeet; Schefske, Jeffrey

2008-03-01

73

Fast construction of overlay networks  

Microsoft Academic Search

An asynchronous algorithm is described for rapidly constructing an overlay network in a peer-to-peer system where all nodes can in principle communicate with each other directly through an underlying network, but each participating node initially has pointers to only a handful of other participants. The output of the mechanism is a linked list of all participants sorted by their identifiers,

Dana Angluin; James Aspnes; Jiang Chen; Yinghua Wu; Yitong Yin

2005-01-01

74

Landsat Data Continuity Mission  

NASA Technical Reports Server (NTRS)

The Landsat Data Continuity Mission (LDCM) is currently under development and is on schedule to launch the 8th satellite in the Landsat series in December of 2012. LDCM is a joint project between the National Aeronautics and Space Administration (NASA) and the United States Geological Survey (USGS). NASA is responsible for developing and launching the flight hardware and on-orbit commissioning and USGS is responsible for developing the ground system and operating the system onorbit after commissioning. Key components of the flight hardware are the Operational Land Imager (OLI), nearing completion by Ball Aerospace & Technologies Corp in Boulder, CO, the Thermal Infrared Sensor (TIRS), being built by NASA's Goddard Space Flight Center and the spacecraft, undergoing integration at Orbital Sciences Corp in Gilbert, Arizona. The launch vehicle will be an Atlas-5 with launch services provided by NASA's Kennedy Space Center. Key ground systems elements are the Mission Operations Element, being developed by the Hammers Corporation, and the Collection Activity Planning Element, Ground Network Element, and Data Processing and Archive System, being developed internally by the USGS Earth Resources Observations and Science (EROS) Center. The primary measurement goal of LDCM is to continue the global coverage of moderate spatial resolution imagery providing continuity with the existing Landsat record. The science goal for this imagery is to monitor land use and land cover, particularly as it relates to global climate change. Together the OLI and TIRS instruments on LDCM replace the ETM+ instrument on Landsat-7 with significant enhancements. The OLI is a pushbroom design instrument where the scanning mechanism of the ETM+ is effectively replaced by a long line of detectors. The OLI has 9 spectral bands with similar spatial resolution to ETM+: 7 of them similar to the reflective spectral bands on ETM+ and two new bands. The two new bands cover (1) the shorter wavelength blue part of the spectrum to help with coastal studies and aerosol analyses/atmospheric correction and (2) an atmospheric water absorption band, where the Earth surface is generally not visible, but Cirrus clouds are, to aid in cloud detection and screening. The radiometry of OLI benefits from improved SNR, dynamic range and quantization. OLI is undergoing system testing with a delivery scheduled for Spring 2011. The TIRS is also a pushbroom design and used QWIPS detectors that require cooling to 43K using a cryocooler. It.has two spectral bands, effectively splitting the ETM+ band 6 in half, that can be used as a split window to aid in atmospheric correction. It has nominally 100 m spatial resolution as opposed to the 60 m of Landsat-7 ETM+: TIRS has commenced integration and test, with a delivery to the spacecraft vendor scheduled for Winter 2011-2012. The Orbital spacecraft currently being integrated for LDCM will have improved capabilities for pointing over previous missions. These capabilities will allow the OLI and TIRS instruments to point off-nadir the equivalent of one WRS-2 path to increase the chances of coverage for high priority targets, particularly in the event of natural disasters. Also, the pointing capability will allow the calibration of the OLI using the sun (roughly weekly), the moon (monthly), stars (during commissioning) and the Earth (at 90 deg from normal orientation, a.k.a., side slither) quarterly. The solar calibration will be used for OLI absolute and relative calibration, the moon for trending the stability of the OLI response, the stars will be used for Line of Sight determination and the side slither will be an alternate OLI and relative gain determination methodology. The spacecraft is scheduled to begin integration with the OLI instrument in Summer 2011. The LDCM data processing and archive system (DPAS), located at USGS EROS, generates the products for distribution to users. Like Landsat-7 this includes an image assessment system for characrizing instrument performance and updating calibration parameters. Products will be generated tha

Markham, Brian; Irons, James; Dabney, Philip

2011-01-01

75

Evaluation of multiband, multitemporal, and transformed LANDSAT MSS data for land cover area estimation. [North Central Missouri  

NASA Technical Reports Server (NTRS)

Sample segments of ground-verified land cover data collected in conjunction with the USDA/ESS June Enumerative Survey were merged with LANDSAT data and served as a focus for unsupervised spectral class development and accuracy assessment. Multitemporal data sets were created from single-date LANDSAT MSS acquisitions from a nominal scene covering an eleven-county area in north central Missouri. Classification accuracies for the four land cover types predominant in the test site showed significant improvement in going from unitemporal to multitemporal data sets. Transformed LANDSAT data sets did not significantly improve classification accuracies. Regression estimators yielded mixed results for different land covers. Misregistration of two LANDSAT data sets by as much and one half pixels did not significantly alter overall classification accuracies. Existing algorithms for scene-to scene overlay proved adequate for multitemporal data analysis as long as statistical class development and accuracy assessment were restricted to field interior pixels.

Stoner, E. R.; May, G. A.; Kalcic, M. T. (principal investigators)

1981-01-01

76

The Next Landsat Satellite: The Landsat Data Continuity Mission  

NASA Technical Reports Server (NTRS)

The Landsat program is one of the longest running satellite programs for Earth observations from space. The program was initiated by the launch of Landsat 1 in 1972. Since then a series of six more Landsat satellites were launched and at least one of those satellites has been in operations at all times to continuously collect images of the global land surface. The Department of Interior (DOI) U.S. Geological Survey (USGS) preserves data collected by all of the Landsat satellites at their Earth Resources Observation and Science (EROS) Center in Sioux Falls, South Dakota. This 40-year data archive provides an unmatched record of the Earth's land surface that has undergone dramatic changes in recent decades due to the increasing pressure of a growing population and advancing technologies. EROS provides the ability for anyone to search the archive and order digital Landsat images over the internet for free. The Landsat data are a public resource for observing, characterizing, monitoring, trending, and predicting land use change over time providing an invaluable tool for those addressing the profound consequences of those changes to society. The most recent launch of a Landsat satellite occurred in 1999 when Landsat 7 was placed in orbit. While Landsat 7 remains in operation, the National Aeronautics and Space Administration (NASA) and the DOI/ USGS are building its successor satellite system currently called the Landsat Data Continuity Mission (LDCM). NASA has the lead for building and launching the satellite that will carry two Earth-viewing instruments, the Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS). The OLI will take images that measure the amount of sunlight reflected by the land surface at nine wavelengths of light with three of those wavelengths beyond the range of human vision. T1RS will collect coincident images that measure light emitted by the land surface as a function of surface temperature at two longer wavelengths well beyond the range of human vision. The DOI/USGS is developing the ground system that will command and control the LDCM satellite in orbit and manage the OLI and TIRS data transmitted by the satellite. DOI/USGS will thus operate the satellite and collect, archive, and distribute the image data as part of the EROS archive. DOI/USGS has committed to renaming LDCM as Landsat 8 following launch. By either name the satellite and its sensors will extend the 40-year archive with images sufficiently consistent with data from earlier Landsat satellites to allow multi-decadal, broad-area studies of our dynamic landscapes. The next Landsat satellite and ground system are on schedule for a January, 2013 launch.

Rons, James R.; Dwyer, John L.; Barsi, Julia A.

2012-01-01

77

20nm MOL overlay case study  

NASA Astrophysics Data System (ADS)

As the process nodes continue to shrink, overlay budgets are approaching theoretical performance of the tools. It becomes even more imperative to improve overlay performance in order to maintain the roadmap for advance integrated circuit manufacturing. One of the critical factors in 20nm manufacturing is the overlay performance between the Middle of Line (MOL) and the Poly layer. The margin between these two layers was a process limiter, it was essential that we maintain a very tight overlay control between these layers. Due to various process and metrology related effects, maintaining good overlay control became a challenge. In this paper we describe the various factors affecting overlay performance and the measures taken to mitigate or eliminate said factors to improve overlay performance.

Subramany, Lokesh; Hsieh, Michael; Li, Chen; Koh, Hui Peng; Cho, David; Golotsvan, Anna; Ramanathan, Vidya; Karur Shanmugam, Ramkumar; Yap, Lipkong

2014-04-01

78

Evaluating diffraction-based overlay  

NASA Astrophysics Data System (ADS)

We evaluate diffraction-based overlay (DBO) metrology using two test wafers. The test wafers have different film stacks designed to test the quality of DBO data under a range of film conditions. We present DBO results using traditional empirical approach (eDBO). eDBO relies on linear response of the reflectance with respect to the overlay displacement within a small range. It requires specially designed targets that consist of multiple pads with programmed shifts. It offers convenience of quick recipe setup since there is no need to establish a model. We measure five DBO targets designed with different pitches and programmed shifts. The correlations of five eDBO targets and the correlation of eDBO to image-based overlay are excellent. The targets of 800nm and 600nm pitches have better dynamic precision than targets of 400nm pitch, which agrees with simulated results on signal/noise ratio. 3? of less than 0.1nm is achieved for both wafers using the best configured targets. We further investigate the linearity assumption of eDBO algorithm. Simulation results indicate that as the pitch of DBO targets gets smaller, the nonlinearity error, i.e., the error in the overlay measurement results caused by deviation from ideal linear response, becomes bigger. We propose a nonlinearity correction (NLC) by including higher order terms in the optical response. The new algorithm with NLC improves measurement consistency for DBO targets of same pitch but different programmed shift, due to improved accuracy. The results from targets with different pitches, however, are improved marginally, indicating the presence of other error sources.

Li, Jie; Tan, Asher; Jung, JinWoo; Goelzer, Gary; Smith, Nigel; Hu, Jiangtao; Ham, Boo-Hyun; Kwak, Min-Cheol; Kim, Cheol-Hong; Nam, Suk-Woo

2012-03-01

79

Status of worldwide Landsat archive  

USGS Publications Warehouse

In cooperation with the International Landsat community, and through the Landsat Technical Working Group (LTWG), NOAA is assembling information about the status of the Worldwide Landsat Archive. During LTWG 9, member nations agreed to participate in a survey of International Landsat data holding and of their archive experiences with Landsat data. The goal of the effort was two-fold; one, to document the Landsat archive to date, and, two, to ensure that specific nations' experience with long-term Landsat archival problems were available to others. The survey requested details such as amount of data held, the format of the archive holdings by Spacecraft/Sensor, and acquisition years; the estimated costs to accumulated process, and replace the data (if necessary); the storage space required, and any member nation's plans that would establish the insurance of continuing quality. As a group, the LTWG nations are concerned about the characteristics and reliability of long-term magnetic media storage. Each nation's experience with older data retrieval is solicited in the survey. This information will allow nations to anticipate and plan for required changes to their archival holdings. Also solicited were reports of any upgrades to a nation's archival system that are currently planned and all results of attempts to reduce archive holdings including methodology, current status, and the planned access rates and product support that are anticipated for responding to future archival usage.

Warriner, Howard W.

1987-01-01

80

Landsat imagery for hydrologic modeling  

NASA Technical Reports Server (NTRS)

The cost and effectiveness of developing land cover information derived from Landsat imagery for hydrologic studies are compared with the cost and effectiveness of conventional sources. The analysis shows that the conventional and Landsat methods are nearly equally effective in providing adequate land cover data for hydrologic studies. The total cost effectiveness analysis demonstrates that the conventional method is cost effective for a study area of less than 26 sq km and that the Landsat method is to be preferred for areas of more than 26 sq km.

Taylor, R. S.; Shubinski, R. P.; George, T. S.

1980-01-01

81

LANDSAT (MSS): Image demographic estimations  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. Two sets of urban test sites, one with 35 cities and one with 70 cities, were selected in the State, Sao Paulo. A high degree of colinearity (0.96) was found between urban and areal measurements taken from aerial photographs and LANDSAT MSS imagery. High coefficients were observed when census data were regressed against aerial information (0.95) and LANDSAT data (0.92). The validity of population estimations was tested by regressing three urban variables, against three classes of cities. Results supported the effectiveness of LANDSAT to estimate large city populations with diminishing effectiveness as urban areas decrease in size.

Dejesusparada, N. (principal investigator); Foresti, C.

1977-01-01

82

Landsat features for agricultural applications  

NASA Technical Reports Server (NTRS)

This paper presents relationships among Landsat MSS bands and selected transformations of them, with emphasis on the Tasseled-Cap Transformation and its Brightness, Greenness variables. It also discusses relationships between reflectance measurements made in the Landsat spectral bands and actual Landsat data. Agronomically oriented analyses of reflectance measurements of wheat throughout a growing season are presented, with a comparison of various green measures, correlation with crop development stage, and examination of the effects of moisture stress. The final example addresses the use of transformed variables in a newly developed approach to forestry change detection.

Malila, W. A.; Lambeck, P. F.; Crist, E. P.; Jackson, R. D.; Pinter, P. J., Jr.

1980-01-01

83

25 Years of Landsat 5  

NASA Video Gallery

Twenty-two years beyond its primary mission lifetime, Landsat 5 is still going strong. It has charted urban growth in Las Vegas, monitored fire scars in Yellowstone National Park, and tracked the r...

84

CNPQ/INPE LANDSAT system  

NASA Technical Reports Server (NTRS)

The current status of the Brazilian LANDSAT facilities is described and main accomplishments are outlined. Receiving, recording, and processing substations and data distribution centers are discussed. Examples of the preliminary TM product produced by the Brazilian station are given.

Parada, N. D. J. (principal investigator); Barbosa, M. N.; Escada, J. B., Jr.

1983-01-01

85

LANDSAT-D refurbishment study  

NASA Technical Reports Server (NTRS)

Requirements for refurbishing the LANDSAT-D spacecraft after its recovery from orbit at the end of a 3-year mission in order to reuse the spacecraft on a second 3-year mission were studied. A schedule of the time required for the refurbishment including the procurement cycle for long lead-time items is developed. The costs of refurbishing and of procuring an entirely new LANDSAT-D spacecraft are compared.

1980-01-01

86

Landsat moves to NASA, DOD  

NASA Astrophysics Data System (ADS)

As the first session of the 101st Congress draws to a close, chairman of the House Committee on Science, Space, and Technology George Brown is looking for a decision on the management, funding, and policy concerning the Landsat program. “The development of a new policy framework for Landsat cannot be postponed any longer,” he said at a November 26 hearing.His concern seems to have been recognized, as on November 25, the National Space Council, under the leadership of Vice President Dan Quayle, announced that the Department of Defense and NASA will take over the Landsat program. In their endorsement of the remote-sensing program, the council said that “global change research and other U.S. government needs beyond Landsat 6 will be provided through the achydroquisition and operation of a Landsat 7. NASA and DOD will undertake the development and operation of this system.” Technical and administrative details of the program are still to be worked out, and funding for Landsat 7 and related activities will be included in the president's FY 1993 budget.

Bush, Susan

87

Landsat Data as a Tool for the Geosciences.  

ERIC Educational Resources Information Center

Applications of the Landsat Thematic Mapper in the fields of pedology, geology, and geomorphology are described. The history of the Landsat program and Landsat products are discussed. Illustrations of different Landsat views are presented. (CW)

Cary, Tina

1990-01-01

88

Bond and Durability of Concrete and Resinous Overlays.  

National Technical Information Service (NTIS)

Tests were made on portland cement and resinous concrete overlays to determine their suitability as overlays for deteriorated concrete bridge decks. Direct shear strengths of overlays bonded with epoxy, portland cement grout, and latex modified cement gro...

H. L. Furr L. L. Ingram

1971-01-01

89

Internet Traffic Engineering without Full Mesh Overlaying  

Microsoft Academic Search

The overlay approach has been widely used by many service providers for traffic engineering in large Internet backbones. In the overlay approach, logical connections are set up between edge nodes to form a full mesh virtual network on top of the physical topology. IP routing is then run over the virtual network. Traffic engineering objectives are achieved through carefully routing

Yufei Wang; Zheng Wang; Leah Zhang

2001-01-01

90

Weld overlay coatings for erosion control  

Microsoft Academic Search

A literature review was made. In spite of similarities between abrasive wear and solid particle erosion, weld overlay hardfacing alloys that exhibit high abrasion resistance may not necessarily have good erosion resistance. The performance of weld overlay hardfacing alloys in erosive environments has not been studied in detail. It is believed that primary-solidified hard phases such as carbides and intermetallic

B. Levin; J. N. DuPont; A. R. Marder

1993-01-01

91

Coloured Overlays and Their Benefit for Reading.  

ERIC Educational Resources Information Center

Presents three studies where children in mainstream schools compared text on white paper with identical text covered in turn by each of 10 differently-colored plastic overlays. Shows consistency with regard to the proportion of children in mainstream education who report beneficial perceptual effects with colored overlays and who demonstrate…

Wilkins, Arnold J.; Lewis, Elizabeth; Smith, Fiona; Rowland, Elizabeth; Tweedie, Wendy

2001-01-01

92

LANDSAT-2 and LANDSAT-3 Flight evaluation report  

NASA Technical Reports Server (NTRS)

Flight performance analysis of LANDSAT 2 and LANDSAT 3 are presented for the period July 1978 to October 1978. Spacecraft operations and orbital parameters are summarized for each spacecraft. Data are provided on the performance and operation of the following subsystems onboard the spacecraft: power; attitude control; command/clock; telemetry; orbit adjust; magnetic moment compensating assembly; unified S band/premodulation processor; electrical interface; thermal narrowband tape recorders; wideband telemetry; attitude measurement sensor; wideband video tape recorders; return beam vidicon; multispectral scanner subsystem; and data collections.

Winchester, T. W.

1978-01-01

93

CFDP for Interplanetary Overlay Network  

NASA Technical Reports Server (NTRS)

The CCSDS (Consultative Committee for Space Data Systems) File Delivery Protocol for Interplanetary Overlay Network (CFDP-ION) is an implementation of CFDP that uses IO' s DTN (delay tolerant networking) implementation as its UT (unit-data transfer) layer. Because the DTN protocols effect automatic, reliable transmission via multiple relays, CFDP-ION need only satisfy the requirements for Class 1 ("unacknowledged") CFDP. This keeps the implementation small, but without loss of capability. This innovation minimizes processing resources by using zero-copy objects for file data transmission. It runs without modification in VxWorks, Linux, Solaris, and OS/X. As such, this innovation can be used without modification in both flight and ground systems. Integration with DTN enables the CFDP implementation itself to be very simple; therefore, very small. Use of ION infrastructure minimizes consumption of storage and processing resources while maximizing safety.

Burleigh, Scott C.

2011-01-01

94

Landsat image data quality studies  

NASA Technical Reports Server (NTRS)

Preliminary results of the Landsat-4 Image Data Quality Analysis (LIDQA) program to characterize the data obtained using the Thematic Mapper (TM) instrument on board the Landsat-4 and Landsat-5 satellites are reported. TM design specifications were compared to the obtained data with respect to four criteria, including spatial resolution; geometric fidelity; information content; and image relativity to Multispectral Scanner (MSS) data. The overall performance of the TM was rated excellent despite minor instabilities and radiometric anomalies in the data. Spatial performance of the TM exceeded design specifications in terms of both image sharpness and geometric accuracy, and the image utility of the TM data was at least twice as high as MSS data. The separability of alfalfa and sugar beet fields in a TM image is demonstrated.

Schueler, C. F.; Salomonson, V. V.

1985-01-01

95

Earth Now! Landsat Image Viewer  

NSDL National Science Digital Library

This viewer lets students see near real-time images from the Landsat 5 Thematic Mapper (TM) and Landsat 7 Enhanced Thematic Mapper Plus (ETM+). When a Landsat satellite passes within range of the ground station at the USGS Center for Earth Resources Observation and Science (EROS), image data are downlinked and displayed in near-real time. When no satellites are within range, the most recent pass is displayed. By viewing the moving display, students can monitor changes in the Earth's surface. An index map and information display shows the path of the satellite, indicates which satellite is currently providing the imagery, and gives the acquisition date and time. A help page and frequently-asked-questions feature are provided to explain how to use the site.

96

Detection of aspen-conifer forest mixes from LANDSAT digital data. [Utah-Idaho Bear River Range  

NASA Technical Reports Server (NTRS)

Aspen, conifer and mixed aspen/conifer forests were mapped for a 15-quadrangle study area in the Utah-Idaho Bear River Range using LANDSAT multispectral scanner data. Digital classification and statistical analysis of LANDSAT data allowed the identification of six groups of signatures which reflect different types of aspen/conifer forest mixing. Photo interpretations of the print symbols suggest that such classes are indicative of mid to late seral aspen forests. Digital print map overlays and acreage calculations were prepared for the study area quadrangles. Further field verification is needed to acquire additional information about the nature of the forests. Single date LANDSAT analysis should be a cost effective means to index aspen forests which are at least in the mid seral phase of conifer invasion. Since aspen canopies tend to obscure understory conifers for early seral forests, a second date analysis, using data taken when aspens are leafless, could provide information about early seral aspen forests.

Jaynes, R. A.; Merola, J. A.

1982-01-01

97

Landsat 8: Promise and Performance  

NASA Astrophysics Data System (ADS)

The National Aeronautics and Space Administration (NASA) launched the Landsat Data Continuity Mission (LDCM) on February 11, 2013 placing the eighth satellite in the Landsat series in orbit. The U.S. Geological Survey assumed responsibility for operations following a 100-day commissioning period and promptly renamed the satellite Landsat 8 on May 30, 2013. The satellite and its sensor payload, the Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS), have performed magnificently since launch. The OLI signal-to-noise performance, for example, exceeds specifications by factors greater than 1.5 for every spectral band. TIRS is providing data with noise-equivalent-changes-in-temperature of less then 0.1 Kelvin compared to requirements of 0.4 Kelvin for its two thermal bands. The geometry of the images is also excellent with band-to-band registration accuracy, for example, of no more than 3.0 m for the OLI bands. The Landsat 8 level 1 data products are orthorectified and registered to the Universal Transverse Mercator cartographic projection with an uncertainty less than 5 m for OLI 30 m pixels and less than 35 m for TIRS 100 m pixels. The only exception to full specification compliance lies with the TIRS radiometric calibration. Discrepancies have been noted between calibrated Landsat 8 thermal data, TIRS Bands 10 and 11, and surface water temperature measurements collected to validate thermal band calibration. Surface water temperatures derived from TIRS data, after correction for atmospheric transmission and emissivity, are warmer than measured surface water temperatures by 2 K or more. This indicates a possible bias or other error in TIRS calibration that places the calibration uncertainty beyond the specified performance of 2 percent. Analysts continue to compare TIRS data to surface temperature measurements to discover the source of the discrepancy. Updates to TIRS calibration coefficients will be incorporated into Landsat 8 data processing as soon as the discrepancy is sufficiently understood. This presentation will report the current performance of Landsat 8 and will discuss the impact of the performance on Landsat data analyses and applications.

Irons, J. R.

2013-12-01

98

Adaptive processing for LANDSAT data  

NASA Technical Reports Server (NTRS)

Analytical and test results on the use of adaptive processing on LANDSAT data are presented. The Kalman filter was used as a framework to contain different adapting techniques. When LANDSAT MSS data were used all of the modifications made to the Kalman filter performed the functions for which they were designed. It was found that adaptive processing could provide compensation for incorrect signature means, within limits. However, if the data were such that poor classification accuracy would be obtained when the correct means were used, then adaptive processing would not improve the accuracy and might well lower it even further.

Crane, R. B.; Reyer, J. F.

1975-01-01

99

A legislator's guide to LANDSAT  

NASA Technical Reports Server (NTRS)

The LANDSAT satellite is an effective tool in meeting the natural resources data requirements of state and federal legislation. The availability of data from the satellite is beginning to have an impact on state legislature activities. An overview of the history, operation, and data analysis techniques, is presented as well as a discussion of the advantages and limitations of this method of remote sensing. Applications are discussed in the areas of (1) land resource planning and management; (2) coastal zone management; (3) agriculture; (4) forestry; (5) routing and siting; (6) environmental monitoring; and (7) geological exploration. National and state sources from which information about LANDSAT technology is available are listed.

1982-01-01

100

The effect of individually-induced processes on image-based overlay and diffraction-based overlay  

NASA Astrophysics Data System (ADS)

In this paper, set of wafers with separated processes was prepared and overlay measurement result was compared in two methods; IBO and DBO. Based on the experimental result, theoretical approach of relationship between overlay mark deformation and overlay variation is presented. Moreover, overlay reading simulation was used in verification and prediction of overlay variation due to deformation of overlay mark caused by induced processes. Through this study, understanding of individual process effects on overlay measurement error is given. Additionally, guideline of selecting proper overlay measurement scheme for specific layer is presented.

Oh, SeungHwa; Lee, Jeongjin; Lee, Seungyoon; Hwang, Chan; Choi, Gilheyun; Kang, Ho-Kyu; Jung, EunSeung

2014-04-01

101

LANDSAT-1 and LANDSAT-2 flight evaluation report  

NASA Technical Reports Server (NTRS)

A flight performance analysis of the LANDSAT-1 spacecraft is presented, and some of the following were examined: (1) orbital parameters; (2) power subsystem; (3) attitude control subsystem; (4) command/clock subsystem; (5) narrowband tape recorders; and (6) magnetic moment compensating assembly.

1977-01-01

102

Overlay improvement roadmap: strategies for scanner control and product disposition for 5-nm overlay  

NASA Astrophysics Data System (ADS)

To keep pace with the overall dimensional shrink in the industry, overlay capability must also shrink proportionally. Unsurprisingly, overlay capability < 10 nm is already required for currently nodes in development, and the need for multi-patterned levels has accelerated the overlay roadmap requirements to the order of 5 nm. To achieve this, many improvements need to be implemented in all aspects of overlay measurement, control, and disposition. Given this difficult task, even improvements involving fractions of a nanometer need to be considered. These contributors can be divided into 5 categories: scanner, process, reticle, metrology, and APC. In terms of overlay metrology, the purpose is two-fold: To measure what the actual overlay error is on wafer, and to provide appropriate APC feedback to reduce overlay error for future incoming hardware. We show that with optimized field selection plan, as well as appropriate within-field sampling, both objectives can be met. For metrology field selection, an optimization algorithm has been employed to proportionately sample fields of different scan direction, as well as proportional spatial placement. In addition, intrafield sampling has been chosen to accurately represent overlay inside each field, rather than just at field corners. Regardless, the industry-wide use of multi-exposure patterning schemes has pushed scanner overlay capabilities to their limits. However, it is now clear that scanner contributions may no longer be the majority component in total overlay performance. The ability to control correctable overlay components is paramount to achieving desired performance. In addition, process (non-scanner) contributions to on-product overlay error need to be aggressively tackled, though we show that there also opportunities available in active scanner alignment schemes, where appropriate scanner alignment metrology and correction can reduce residuals on product. In tandem, all these elements need to be in place to achieve the necessary overlay roadmap capability for current development efforts.

Felix, Nelson M.; Gabor, Allen H.; Menon, Vinayan C.; Longo, Peter P.; Halle, Scott D.; Koay, Chiew-Seng; Colburn, Matthew E.

2011-03-01

103

Landsat 7 Science Data Processing: An Overview  

NASA Technical Reports Server (NTRS)

The Landsat 7 Science Data Processing System, developed by NASA for the Landsat 7 Project, provides the science data handling infrastructure used at the Earth Resources Observation Systems (EROS) Data Center (EDC) Landsat Data Handling Facility (DHF) of the United States Department of Interior, United States Geological Survey (USGS) located in Sioux Falls, South Dakota. This paper presents an overview of the Landsat 7 Science Data Processing System and details of the design, architecture, concept of operation, and management aspects of systems used in the processing of the Landsat 7 Science Data.

Schweiss, Robert J.; Daniel, Nathaniel E.; Derrick, Deborah K.

2000-01-01

104

Covariance hypotheses for LANDSAT data  

NASA Technical Reports Server (NTRS)

Two covariance hypotheses are considered for LANDSAT data acquired by sampling fields, one an autoregressive covariance structure and the other the hypothesis of exchangeability. A minimum entropy approximation of the first structure by the second is derived and shown to have desirable properties for incorporation into a mixture density estimation procedure. Results of a rough test of the exchangeability hypothesis are presented.

Decell, H. P.; Peters, C.

1983-01-01

105

Landsat Image Mosaic of Antarctica  

USGS Publications Warehouse

Description Fact sheet introduces the Landsat Image Mosaic of Antarctica (LIMA) with images from a section of the mosaic over McMurdo Station, descriptions of the four versions of LIMA, where to access and download LIMA, and a brief explanation of the Antarctic Web portal.

U.S. Geological Survey

2007-01-01

106

Landsat and Thermal Infrared Imaging  

NASA Technical Reports Server (NTRS)

The purpose of this chapter is to describe the collection of thermal images by Landsat sensors already on orbit and to introduce the new thermal sensor to be launched in 2013. The chapter describes the thematic mapper (TM) and enhanced thematic mapper plus (ETM+) sensors, the calibration of their thermal bands, and the design and prelaunch calibration of the new thermal infrared sensor (TIRS).

Arvidson, Terry; Barsi, Julia; Jhabvala, Murzy; Reuter, Dennis

2012-01-01

107

Using population statistics for a first look at the utility of Landsat data for urban areas  

NASA Technical Reports Server (NTRS)

The paper reviews the Image Based Information System (IBIS), developed at the Jet Propulsion Laboratory (JPL) which provided the city of Los Angeles with Landsat land use data in a format compatible with the city's land use and population files. Landsat data are compared to other land use files and the comparisons are discussed as an attempt to establish a level of validity. Relationships between population and Landsat data are investigated and reveal the strengths and weaknesses of the use of such data for urban areas. Finally, it is noted that the project verified the flexibility of IBIS for reducing and delivering Landsat data to users lacking the ability to process raw satellite data tapes and points to the system as a model for a potential national census of land use.

Landini, A. J.; Mcleod, R. G.

1979-01-01

108

Polishing Your Transparencies: Mounting, Masking, Overlays.  

ERIC Educational Resources Information Center

This brief guide discusses the mounting of overhead transparencies on frames, the types of mounts, the proper masking for presentation, and the use of overlays. Numerous line drawings provide the reader with a helpful visual reference. (RAO)

Jobe, Holly; Cannon, Glenn

109

Bonded Concrete Overlays: Construction and Performance.  

National Technical Information Service (NTIS)

Several bonded concrete overlays have recently been placed on street, highway, and airfield pavements using new equipment and techniques. This report summarizes the current state of the art and industry experience as well as reviewing procedures and perfo...

M. I. Darter E. J. Barenberg

1980-01-01

110

Structured Overlay Network for File Distribution  

NASA Astrophysics Data System (ADS)

The file distribution from a source node to n sink nodes along a structured overlay network can be done in time ?(logn). In this paper, we model the problem of finding an optimal overlay network for file distribution as a combinatorial optimization problem, i.e., finding a weighted spanning tree which connects the source node and sink nodes and has the minimum file distribution time. We use an edge-based file distribution protocol, in which after a node receives a file it then transfers the file to its neighbor nodes one after another in a sequential order. We give the formulation of file distribution time, and use it as the objective function. The corresponding combinatorial optimization problem is NP-hard in general. We present a heuristic algorithm which derives an overlay network with file distribution time ?(logn) and show that the derived overlay network is optimal if the file transfer delays between all pairs of nodes are the same.

Fan, Hongbing; Wu, Yu-Liang

111

Solidification of an alloy 625 weld overlay  

Microsoft Academic Search

The solidification behavior (microsegregation, secondary phase formation, and solidification temperature range) of an Alloy\\u000a 625 weld overlay deposited on 2.25Cr - 1Mo steel by gas metal arc welding was investigated by light and electron optical microscopy,\\u000a electron microprobe, and differential thermal analysis techniques. The overlay deposit was found to terminate solidification\\u000a at ? 1216 C by a?\\/Laves eutectic-type reaction. The

J. N. DuPont

1996-01-01

112

Polymer concrete overlay on SH-51, bridge deck  

NASA Astrophysics Data System (ADS)

A thin resinous overlay was placed on a sound bridge deck in Oklahoma to evaluate its performance over one year using various physical tests. The evaluation shows how well the overlay protects the reinforcing steel from corrosion due to deicing salts. The steps leading to the construction of the overlay are detailed as well as the actual placing of the overlay. The results of various physical tests are reported for both before and after the overlay.

Borg, T. M.

1982-06-01

113

LANDSAT-1 and LANDSAT-2 flight evaluation report  

NASA Technical Reports Server (NTRS)

The LANDSAT-1 spacecraft was launched from the Western Test Range on 23 July 1972, at 18:08:06.508Z. The launch and orbital injection phase of the space flight was nominal and deployment of the spacecraft followed predictions. Orbital operations of the spacecraft and payload subsystems were satisfactory through Orbit 147, after which an internal short circuit disabled one of the Wideband Video Tape Recorders (WBVTR-2). Operations resumed until Orbit 196, when the Return Beam Vidicon failed to respond when commanded off. The RBV was commanded off via alternate commands. LANDSAT-1 continued to perform its imaging mission with the Multispectral Scanner and the remaining Wideband Video Tape Recorder providing image data.

1976-01-01

114

Logical Networks: Towards Foundations for Programmable Overlay Networks and Overlay Computing Systems  

Microsoft Academic Search

We propose and discuss foundations for programmable over- lay networks and overlay computing systems. Such overlays are built over a large number of distributed computational individuals, virtually organized in colonies, and ruled by a leader (broker) who is elected or imposed by system administrators. Every individual asks the broker to log in the colony by declaring the resources that can

Luigi Liquori; Michel Cosnard

2007-01-01

115

Landsat imagery: a unique resource  

USGS Publications Warehouse

Landsat satellites provide high-quality, multi-spectral imagery of the surface of the Earth. These moderate-resolution, remotely sensed images are not just pictures, but contain many layers of data collected at different points along the visible and invisible light spectrum. These data can be manipulated to reveal what the Earth’s surface looks like, including what types of vegetation are present or how a natural disaster has impacted an area (Fig. 1).

Miller, H.; Sexton, N.; Koontz, L.

2011-01-01

116

Landsat analysis of lake quality  

NASA Technical Reports Server (NTRS)

The trophic status of a number of inland lakes in Wisconsin has been assessed. The feasibility of using both photographic and digital representations of Landsat imagery was investigated during the lake classification project. The result of the investigation has been a semi-automatic data acquisition and handling system which, in conjunction with an analytical categorization scheme, can be used to classify all the significant lakes in the state.

Scarpace, F. L.; Fisher, L. T.; Holmquist, K. W.

1979-01-01

117

Stereocorrelation of Landsat TM images  

NASA Technical Reports Server (NTRS)

A digital elevation model (DEM) developed from Landsat TM images of a rugged terrain area in north Georgia by automated stereocorrelation techniques yielded an rms error (z), RMSE(z), value of + or - 42 m. Based on the B/H ratio of 0.18 for the Landsat data, this Z-error corresponds to a planimetric correlation accuracy of about + or - 0.3 pixels, confirming that precise correlation can be achieved with operational satellite data. Contours at a 100-m interval interpolated from the DEM show a deviation of + or - 33 m from reference contours obtained from existing 1:24,000-scale maps. The 28.5-m pixel resolution and the weak B/H ratio impose limitations on the accuracy that can be achieved with Landsat TM data. However, it is anticipated that RMSE(z) values of + or - 10 m or less can be achieved with SPOT-1 panchromatic stereo images of 10-m resolution recorded at B/H ratios of 0.5 to 1.0. DEMs generated by stereocorrelation techniques can be used to create orthoimages, perspective views, and topographic map products.

Ehlers, Manfred; Welch, R.

1987-01-01

118

Landsat: Making a Difference, One User at a Time  

NASA Video Gallery

The Landsat Data Continuity Mission will continue and improve upon the 40-year-old Landsat program. This video examines two uses of Landsat data to monitor agriculture. Both wineries and timber com...

119

Solidification of an alloy 625 weld overlay  

NASA Astrophysics Data System (ADS)

The solidification behavior (microsegregation, secondary phase formation, and solidification temperature range) of an Alloy 625 weld overlay deposited on 2.25Cr - 1Mo steel by gas metal arc welding was investigated by light and electron optical microscopy, electron microprobe, and differential thermal analysis techniques. The overlay deposit was found to terminate solidification at ? 1216 °C by a ?/Laves eutectic-type reaction. The Laves phase was highly enriched in Nb, Mo, and Si. The solidification reaction and microsegregation potential of major alloying elements in the overlay deposit are compared to other Nb-bearing Ni base alloys and found to be very similar to those for Alloy 718. Solidification cracks observed in the overlay were attributed to the wide solidification temperature range (?170 °C) and formation of interdendritic ( ?+Laves) constituent. Reasonable agreement is obtained between the calculated and measured volume percent ( ?+Laves) constituent with the Scheil equation by treating the overlay system as a simple ?-Nb “binary” and using an experimentally determined k Nb value from electron microprobe data.

Dupont, J. N.

1996-11-01

120

Solidification of an alloy 625 weld overlay  

SciTech Connect

The solidification behavior (microsegregation, secondary phase formation, and solidification temperature range) of an Alloy 625 weld overlay deposited on 2.25Cr-1Mo steel by gas metal arc welding was investigated by light and electron optical microscopy, electron microprobe, and differential thermal analysis techniques. The overlay deposit was found to terminate solidification at {approx}1,216 C by a {gamma}/Laves eutectic-type reaction. The Laves phase was highly enriched in Nb, Mo, and Si. The solidification reaction and microsegregation potential of major alloying elements in the overlay deposit are compared to other Nb-bearing Ni base alloys and found to be very similar to those for Alloy 718. Solidification cracks observed in the overlay were attributed to the wide solidification temperature range ({approx}170 C) and formation of interdendritic ({gamma} + Laves) constituent. Reasonable agreement is obtained between the calculated and measured volume percent ({gamma} + Laves) constituent with the Scheil equation by treating the overlay system as a simple {gamma}-Nb binary and using an experimentally determined k{sub Nb} value from electron microprobe data.

DuPont, J.N. [Lehigh Univ., Bethlehem, PA (United States). Energy Research Center

1996-11-01

121

Overlay breakdown methodology on immersion scanner  

NASA Astrophysics Data System (ADS)

In the last years a flourishing number of techniques such as High Order Control or mappers have been proposed to improve overlay control. However a sustainable improvement requires sometimes understanding the underlying causes of the overlay limiting factors in order to remove them when possible or at least to keep them under control. Root cause finding for overlay error is a tough task due the very high number of influencing parameters and the interaction of the usage conditions. This paper presents a breakdown methodology to deal with this complexity and to find the contributors of overlay error variation. We use a Partial Least Squares (PLS) algorithm to isolate the key contributors for correctable terms and a field-to-field linear regression technique to highlight the main causes of residuals. We present a study carried out on 45nm CMOS contact-gate overlay over 687 production wafers exposed in an ASML TWINSCAN XT:1700i Immersion scanner. We present the results of the correlations with the 180 process and equipment variables used for this study. For each isolated contributor we propose an explanation of the underlying physical phenomenon and solutions.

Lam, Auguste; Pasqualini, Francois; de Caunes, Jean; Gatefait, Maxime

2010-03-01

122

Robotic weld overlay coatings for erosion control  

NASA Astrophysics Data System (ADS)

The erosion of materials by the impact of solid particles has received increasing attention during the past twenty years. Recently, research has been initiated with the event of advanced coal conversion processes in which erosion plays an important role. The resulting damage, termed Solid Particle Erosion (SPE), is of concern primarily because of the significantly increased operating costs which result in material failures. Reduced power plant efficiency due to solid particle erosion of boiler tubes and waterfalls has led to various methods to combat SPE. One method is to apply coatings to the components subjected to erosive environments. Protective weld overlay coatings are particularly advantageous in terms of coating quality. The weld overlay coatings are essentially immune to spallation due to a strong metallurgical bond with the substrate material. By using powder mixtures, multiple alloys can be mixed in order to achieve the best performance in an erosive environment. However, a review of the literature revealed a lack of information on weld overlay coating performance in erosive environments which makes the selection of weld overlay alloys a difficult task. The objective of this project is to determine the effects of weld overlay coating composition and microstructure on erosion resistance. These results will lead to a better understanding of erosion mitigation in CFB's.

123

Acquisition and preprocessing of LANDSAT data  

NASA Technical Reports Server (NTRS)

The original configuration of the GSFC data acquisition, preprocessing, and transmission subsystem, designed to provide LANDSAT data inputs to the LACIE system at JSC, is described. Enhancements made to support LANDSAT -2, and modifications for LANDSAT -3 are discussed. Registration performance throughout the 3 year period of LACIE operations satisfied the 1 pixel root-mean-square requirements established in 1974, with more than two of every three attempts at data registration proving successful, notwithstanding cosmetic faults or content inadequacies to which the process is inherently susceptible. The cloud/snow rejection rate experienced throughout the last 3 years has approached 50%, as expected in most LANDSAT data use situations.

Horn, T. N.; Brown, L. E.; Anonsen, W. H. (principal investigators)

1979-01-01

124

Weld overlay coatings for erosion control  

SciTech Connect

A literature review was made. In spite of similarities between abrasive wear and solid particle erosion, weld overlay hardfacing alloys that exhibit high abrasion resistance may not necessarily have good erosion resistance. The performance of weld overlay hardfacing alloys in erosive environments has not been studied in detail. It is believed that primary-solidified hard phases such as carbides and intermetallic compounds have a strong influence on erosion resistance of weld overlay hardfacing alloys. However, relationships between size, shape, and volume fraction of hard phases in a hardfacing alloys and erosion resistance were not established. Almost all hardfacing alloys can be separated into two major groups based upon chemical compositions of the primary solidified hard phases: (a) carbide hardening alloys (Co-base/carbide, WC-Co and some Fe base superalloys); and (b) intermetallic hardening alloys (Ni-base alloys, austenitic steels, iron-aluminides).

Levin, B.; DuPont, J.N.; Marder, A.R.

1993-03-03

125

A spectral overlay method for dissimilar materials  

NASA Technical Reports Server (NTRS)

The spectral overlay method is applied to examine the stress distribution along the interface between the two different materials. The essential feature of the spectral overlay method is that the high resolution of localized steep gradients can be achieved by overlaying a spectral interpolant on a standard finite element mesh. In order to evaluate this method and compare it with conventional finite element method, a test problem with high gradients in Poisson equation has been devised. The results show that this method is very powerful in capturing the shape of the gradient field and its peak value. Solutions for two problems with interfaces between dissimilar materials are then given to illustrate the effectiveness of this method.

Belytschko, T.; Lu, Y. Y.; Gu, L.

1992-01-01

126

EUV overlay strategy for improving MMO  

NASA Astrophysics Data System (ADS)

EUV lithography (EUVL) is the most promising technology to extend the resolution limit, and is expected to be used if the enough source power is delivered and mask defect mitigation method is developed. However, even in that case, the number of EUV steps will be restricted by its high cost, and ArF immersion will still take a major role in the chip manufacturing. Therefore, it is important to check and improve the mix-match overlay (MMO) between EUV and ArF immersion steps. In this paper, we evaluate EUV MMO with ArF immersion system by comparing with dedicated chuck overlay (DCO). The major contributors on MMO are random and field component from overlay analysis. MMO is expected to be below 3nm by applying 18para CPETM(correction per exposure) and RegCTM(Registraion error correction). We consider High oder CPETM need to be developed for further improvement.

Lee, Byoung-Hoon; Lee, Inhwan; Hyun, Yoonsuk; Kim, SeoMin; Lim, Chang-Moon; Kim, Myoung Soo; Park, Sung-ki

2014-04-01

127

LANDSAT-4 and LANDSAT-5 Multispectral Scanner Coherent Noise Characterization and Removal  

NASA Technical Reports Server (NTRS)

A technique is described for characterizing the coherent noise found in LANDSAT-4 and LANDSAT-5 MSS data and a companion technique for filtering out the coherent noise. The techniques are demonstrated on LANDSAT-4 and LANDSAT-5 MSS data sets, and explanations of the noise pattern are suggested in Appendix C. A cookbook procedure for characterizing and filtering the coherent noise using special NASA/Goddard IDIMS functions is included. Also presented are analysis results from the retrofitted LANDSAT-5 MSS sensor, which shows that the coherent noise has been substantially reduced.

Tilton, James C.; Alford, William L.

1988-01-01

128

Robotic weld overlay coatings for erosion control  

SciTech Connect

Twelve weld overlay hardfacing alloys have been selected for preliminary erosion testing based on a literature review These alloys have been separated into three major groups: (1) Cobalt containing alloys, (2) Nickel-base alloys, (3) Iron base alloys. These alloys are being applied to carbon steel substrates and will undergo preliminary erosion testing to identify candidates weld overlay alloys for erosion control in CFB boilers. The candidate alloys selected from the preliminary erosion tests will then undergo more detailed evaluations in future research.

Levin, B.F.; Dupont, J.N.; Marder, A.R.

1993-04-18

129

KML Super Overlay to WMS Translator  

NASA Technical Reports Server (NTRS)

This translator is a server-based application that automatically generates KML super overlay configuration files required by Google Earth for map data access via the Open Geospatial Consortium WMS (Web Map Service) standard. The translator uses a set of URL parameters that mirror the WMS parameters as much as possible, and it also can generate a super overlay subdivision of any given area that is only loaded when needed, enabling very large areas of coverage at very high resolutions. It can make almost any dataset available as a WMS service visible and usable in any KML application, without the need to reformat the data.

Plesea, Lucian

2007-01-01

130

Low-cost LANDSAT processing system  

NASA Technical Reports Server (NTRS)

LANDSAT analysis system is assembled from commercially available components at relatively low cost. Small-scale system is put together for price affordable for state agencies and universities. It processes LANDSAT data for subscene areas on repetitive basis. Amount of time required for processing decreases linearly with number of classifications desired. Computer programs written in FORTRAN IV are available for analyzing data.

Faust, N. L.; Hooper, N. J.; Spann, G. W.

1980-01-01

131

LANDSAT-D Mission Operations Review (MOR)  

NASA Technical Reports Server (NTRS)

Portions of the LANDSAT-D systems operation plan are presented. An overview of the data processing operations, logistics and other operations support, prelaunch and post-launch activities, thematic mapper operations during the scrounge period, and LANDSAT-D performance evaluation is given.

1982-01-01

132

Global Web-Enabled Landsat Data (Invited)  

NASA Astrophysics Data System (ADS)

The 40+ year series of Landsat satellites provides the longest temporal record of space-based observations acquired with spatial resolutions appropriate for monitoring anthropogenic change. The need for 'higher-level' Landsat products, i.e., beyond currently available radiometrically and geometrically corrected Landsat scenes, has been advocated by the user community and by the Landsat science team. The NASA funded Web-enabled Landsat Data (WELD) project has demonstrated this capability by systematically generating 30m weekly, seasonal, monthly and annual composited Landsat mosaics of the conterminous United States (CONUS) and Alaska for 10+ years (http://weld.cr.usgs.gov/). Recently, the WELD code has been ported to the NASA Earth Exchange (NEX) high performance super computing and data platform to generate global 30m WELD products from contemporaneous Landsat 5 and 7 data. The WELD products and select applications that take advantage of the consistently processed WELD time series are showcased. Prototype global monthly 30m products and plans to expand the production to provide Landsat 30m higher level products for any terrestrial non-Antarctic location for six 3-year epochs from 1985 to 2010 are presented. Prototype monthly global NEX 30m WELD product

Roy, D. P.; Kovalskyy, V.; Kommareddy, I.; Votava, P.; Nemani, R. R.; Egorov, A.; Hansen, M.; Yan, L.

2013-12-01

133

LANDSAT D operations control center study  

NASA Technical Reports Server (NTRS)

Various aspects of the planned LANDSAT D system are discussed. LANDSAT D incorporates the Thematic Mapper (TM) as a sensor, it utilizes the Multi-mission Modular Spacecraft (MMS), it makes use of the Tracking and Data Relay Satellite System (TDRSS) and it employs a more advanced ground system. Each of these represent significant improvements in the state-of-the-art.

Alexander, L.; Brown, G.; Clemson, B.; Efner, J.; Engelberg, N.; Owen, J.; Winchester, T.

1977-01-01

134

Landsat Map Teacher Training: A Supervisor's Introduction.  

ERIC Educational Resources Information Center

Discusses the advantages of using Landsat imagery rather than traditional maps and the need for pre- and inservice teacher education on how to interpret information from remote sensing systems. Identifies sources of information and assistance for planning inservice programs and using Landsat imagery in the classroom. (DC)

Kirman, Joseph M.

1981-01-01

135

Investigation of Various Factors Affecting Bond in Bonded Concrete Overlays.  

National Technical Information Service (NTIS)

Bonded concrete overlays (BCO) are rapidly becoming a preferred strategy for Texas highway rehabilitation projects. These overlays have worked well in most areas, but have had occasional problems with debonding and subsequent cracking. The report describe...

D. P. Whitney P. Isis B. F. McCullough D. W. Fowler

1992-01-01

136

Accuracy of diffraction-based and image-based overlay  

NASA Astrophysics Data System (ADS)

There is no overlay standard in the world. For critical dimension (CD), we may use the VLSI standard or programmed pitch offsets to determine the CD accuracy or CD sensitivity. Programmed overlay offsets can provide relatively accurate sub-nanometer level overlay splits but it is only on a single layer and does not contain layer-to-layer process variations. The splits of scanner magnification can check the trend of overlay sensitivity but it cannot provide the exact value of overlay offsets. Transmission electron microscopes (TEM) can be used as a final overly error verification tool. However, TEM sample preparation for after-development-inspection (ADI) will introduce even more sample distortion errors. Therefore, unlike CD metrology, there is no clean and systematic way to verify the accuracy of overlay metrology. These technical barriers necessitate matching diffraction-based overlay and image-based overlay, especially for sub-nanometer point-to-point matching requirement. In this paper, we compare the correlation of ADI to after-etch-inspection (AEI) by using image-based box-in-box overlay measurement and diffraction-based overlay measurement on the same wafer. The ADI-to-AEI overlay data consistency plays a key role for lithography overlay APC success and AEI overlay should be treated as the final standard for overlay accuracy. We found that process-induced asymmetric profiles of overlay marks will lead to ADI-to-AEI overlay bias. This bias is proportional to the degree of profile asymmetry and different color/wavelength have different sensitivity to this ADI-to-AEI bias. Our experimental results show that the ADI-to-AEI overlay data bias can indeed be significantly improved by selecting the color/wavelength with minimum sensitivity to the asymmetry profile. These results make us believe that overlay metrology recipe setup is quite critical no matter for image-based overlay or diffraction-based overlay. Otherwise, problematic overlay data will be taken into APC feedback loop and lead to wrong overlay correction.

Ke, Chih-Ming; Huang, Guo-Tsai; Huang, Jacky; Lee, Rita

2011-03-01

137

A location-aware peer-to-peer overlay network  

Microsoft Academic Search

SUMMARY This work describes a novel location-aware, self-organizing, fault-tolerant peer-to-peer (P2P) overlay network, referred to as Laptop. Network locality-aware considerations are a very important metric for designing a P2P overlay network. Several network proximity schemes have been proposed to enhance the routing efficiency of existing DHT-based overlay networks. However, these schemes have some drawbacks such as high overlay network and

Chi-jen Wu; De-kai Liu; Ren-hung Hwang

2007-01-01

138

An Overlay Tree Building Control Protocol  

Microsoft Academic Search

TBCP is a generic ree Building Control Protocol designedto build overlay spanning trees among participants of a multicast session,without any specific help from the network routers. TBCP therefore fallsinto the general category of protocols and mechanisms often referred toas Application-Level Multicasting. TBCP is an efficient, distributed protocolthat operates with partial knowledge of the group membershipand restricted network topology information. One

Laurent Mathy; Roberto Canonico; David Hutchison

2001-01-01

139

Robotic weld overlay coatings for erosion control  

NASA Astrophysics Data System (ADS)

Research is being conducted to develop criteria for selecting weld overlay coatings for erosion mitigation in circulated fluidized beds. Twelve weld overlay alloys were deposited on 1018 steel substrates using plasma arc welding. Ten samples from each coating were prepared for erosion testing. All selected coatings were erosion tested at 400C and their erosion resistance and microstructure evaluated. Steady state erosion rates were similar for several weld overlay coatings (Ultimet, Inconel-625, Iron-Aluminide, 316L SS, and High Chromium Cast Iron) and were considerably lower than the remaining coating evaluated. These coatings had different base (Co, Fe, Ni-base). No correlations were found between room temperature microhardness of the weld overlay coatings and their erosion resistance at elevated temperature, although this criteria is often thought to be an indicator of erosion resistance. It was suggested that the coatings that showed similar erosion rates may have similar mechanical properties such as fracture strength, toughness and work hardening rates at this temperature. During the past quarter, Iron-Aluminide, Inconel-625, and 316L SS coatings were selected for more detailed investigations based upon the preliminary erosion test results. Microhardness tests were performed on eroded samples to determine the size of the work hardened zone and change in coatings hardness due to erosion. The work hardened zone was correlated with erosion resistance of the coatings. Additional Iron-Aluminide, Inconel-625, and 316L SS coatings were deposited on 1018 steel substrates.

Levin, B. F.; Dupont, J. N.; Marder, A. R.

1994-01-01

140

Investigation of Iron Aluminide Weld Overlays  

Microsoft Academic Search

Conventional fossil fired boilers have been retrofitted with low NO(sub)x burners in order for the power plants to comply with new clean air regulations. Due to the operating characteristics of these burners, boiler tube sulfidation corrosion typically has been enhanced resulting in premature tube failure. To protect the existing panels from accelerated attack, weld overlay coatings are typically being applied.

S. W. Banovic; J. B. DuPont; B. F. Levin; A. R. Marder

1999-01-01

141

Secure Aggregation in Large Scale Overlay Networks  

Microsoft Academic Search

Overlay networks have been very useful in solving large scale data dissemination problems. In this paper, we consider the case of data gathering which is the inverse of dissemination problem. In particular, we focus on a scenario where an organization or a constellation of organizations is interested in gathering data from large number of nodes spread across the administrative boundaries.

Waseem Ahmad; Ashfaq A. Khokhar

2006-01-01

142

Scalability in Adaptive Multi-Metric Overlays  

Microsoft Academic Search

Increasing application requirements have placed heavy emphasis on building overlay networks to efficiently de- liver data to multiple receivers. A key performance chal- lenge is simultaneously achieving adaptivity to changing network conditions and scalability to large numbers of users. In addition, most current algorithms focus on a sin- gle performance metric, such as delay or bandwidth, par- ticular to individual

Adolfo Rodriguez; Dejan Kostic; Amin Vahdat

2004-01-01

143

MIPv6 experimental evaluation using overlay networks  

Microsoft Academic Search

The commercial deployment of Mobile IPv6 has been hastened by the concepts of Inte- grated Wireless Networks and Overlay Networks, which are present in the notion of the forthcoming generation of wireless communications. Individual wireless access networks show limitations that can be overcome through the integration of different technologies into a single unified platform (i.e., 4G systems). This paper summarises

Pablo Vidales; Carlos Jesus Bernardos; Ignacio Soto; David N. Cottingham; Javier Baliosian; Jon Crowcroft

2007-01-01

144

Arigatoni: A Simple Programmable Overlay Network  

Microsoft Academic Search

We design a lightweight Overlay Network, called Ari- gatoni, that is suitable to deploy the Global Comput- ing Paradigm over the Internet. Communications over the behavioral units of the model are performed by a simple communication protocol. Basic Global Comput- ers can communicate by first registering to a brokering service and then by mutually asking and oering ser- vices, in

Didier Benza; Michel Cosnard; Luigi Liquori; Marc Vesin

2006-01-01

145

A Dynamic Mechanism for Distributed Optimization of Overlay Multicast Tree  

Microsoft Academic Search

To enhance the performance of overlay multicast networks, the overlay multicast tree should be optimized. This optimization prob- lem is a minimum diameter, degree-limited spanning tree (MDDLST) problem which is known to be NP-Hard. We present a new scheme to optimize an overlay multicast tree dynamically. Our algorithm can adapt the tree structure to the dynamic membership and network situation.

Han Choe; Seongho Cho; Chongkwon Kim

2004-01-01

146

Overview of the Landsat-7 Mission  

NASA Technical Reports Server (NTRS)

Landsat-7 is scheduled for launch on April 15 from the Western Test Range at Vandenberg Air Force Base, Calif., on a Delta-H expendable launch vehicle. The Landsat 7 satellite consists of a spacecraft bus being provided by Lockheed Martin Missiles and Space (Valley Forge, Pa.) and the Enhanced Thematic Mapper Plus instrument built by Raytheon (formerly Hughes) Santa Barbara Remote Sensing (Santa Barbara, Calif.). The instrument on board Landsat 7 is the Enhanced Thematic Mapper Plus (ETM+). ETM+ improves upon the previous Thematic Mapper (TM) instruments on Landsat's 4 and 5 (Fig. la and lb). It includes the previous 7 spectral bands measuring reflected solar radiation and emitted thermal emissions but, in addition, includes a new 15 in panchromatic (visible-near infrared) band. The spatial resolution of the thermal infrared band has also been improved to 60 m. Both the radiometric precision and accuracy of the sensor are also improved from the previous TM sensors. After being launched into a sun-synchronous polar orbit, the satellite will use on-board propulsion to adjust its orbit to a circular altitude of 438 miles (705 kilometers) crossing the equator at approximately 10 a.m. on its southward track. This orbit will place Landsat 7 along the same ground track as previous Landsat satellites. The orbit will be maintained with periodic adjustments for the life of the mission. A three-axis attitude control subsystem will stabilize the satellite and keep the instrument pointed toward the Earth to within 0.05 degrees. Later this year, plans call for the NASA Earth Observation System (EOS) Terra (AM-1) observatory and the experimental EO-1 mission to closely follow Landsat-7's orbit to support synergistic research and applications from this new suite of terrestrial sensor systems. Landsat is the United States' oldest land-surface observation satellite system, with satellites continuously operating since 1972. Although the program has scored numerous successes in scientific and resource-management applications, Landsat has had a tumultuous history of management and funding changes over its nearly 27-year history. Landsat-7 marks a new direction in the program to reduce the cost of data and increase systematic global coverage for use in global change research as well as commercial and regional applications. With the passage of the Land Remote Sensing Policy Act in 1992, oversight of the Landsat program began to shift from the commercial sector to the federal government. NASA integrated Landsat-7 into its EOS science program in 1994. Landsat-7 is managed and operated jointly by NASA and U.S. Geological Survey (USGS). As a result, the costs of acquiring observations from

Williams, Darrel; Irons, James; Goward, Samuel N.; Masek, Jefery

1999-01-01

147

Accessing free Landsat data via the Internet: Africa's challenge  

Microsoft Academic Search

Since January 2008, the US Department of Interior\\/US Geological Survey has been providing terrain-corrected Landsat data over the Internet for free. This letter reports the size and proportion of the US Landsat archive that is over Africa by each Landsat sensor, discusses the implications of missing data and highlights the current bandwidth constraints on users accessing free Landsat data over

David P. Roy; Junchang Ju; Cheikh Mbow; Philip Frost; Tom Loveland

2010-01-01

148

Classification and area estimation of land covers in Kansas using ground-gathered and LANDSAT digital data  

NASA Technical Reports Server (NTRS)

Ground-gathered data and LANDSAT multispectral scanner (MSS) digital data from 1981 were analyzed to produce a classification of Kansas land areas into specific types called land covers. The land covers included rangeland, forest, residential, commercial/industrial, and various types of water. The analysis produced two outputs: acreage estimates with measures of precision, and map-type or photo products of the classification which can be overlaid on maps at specific scales. State-level acreage estimates were obtained and substate-level land cover classification overlays and estimates were generated for selected geographical areas. These products were found to be of potential use in managing land and water resources.

May, G. A.; Holko, M. L.; Anderson, J. E.

1983-01-01

149

LANDSAT D user data processing study  

NASA Technical Reports Server (NTRS)

The major expected users of the LANDSAT D system and a preliminary system design of their required facilities are investigated. This system design will then be costed in order to provide an estimate of the incremental user costs necessitated by LANDSAT D. One major use of these cost estimates is as part of an overall economic cost/benefit argument being developed for the LANDSAT D system. The implication of this motive is key; the system design (and corresponding cost estimates) must be a credible one, but not necessarily an optimum one.

1976-01-01

150

Landsat/4/Global Positioning System navigation results  

NASA Technical Reports Server (NTRS)

An experimental GPSPAC flown on the Landsat-4 spacecraft was the first spaceborne navigation system to use the NAVSTAR Global Position System (GPS). In order to validate the accuracy and reliability of GPSPAC orbit solutions, definitive Landsat-4 ephemerides, derived from ground based tracking data, were generated and compared with GPSPAC estimates. In addition, Landsat-4 orbital solutions were reconstructed from raw GPS measurement data with a GPSPAC navigation simulator program using different Kalman filter constants. Ephemeris comparisons and simulator results are presented, as well as recommendations for the navigation filter.

Heuberger, H.; Church, L.

1984-01-01

151

Landsat - Current and future capabilities for agriculture  

NASA Technical Reports Server (NTRS)

The potential of the Landsat spacecraft in applications related to agriculture is demonstrated by the examples of assessing the damage to the Brazilian coffee crop due to freezing temperatures on July 17-18, 1975; and damage assessment in the state of Iowa, following a tornado which struck a corn and soybean producing region on June 13, 1976. Some techniques which have been used to measure snow covers on the basis of Landsat data are also noted. The advantages that are expected to accrue from the installation of sophisticated equipment on the third and fourth Landsat spacecraft, scheduled to be launched in 1978 and 1981, respectively, are reviewed.

Walter, L. S.

1977-01-01

152

LANDSAT US standard catalog, 1-31 December 1975. [LANDSAT imagery for December, 1975  

NASA Technical Reports Server (NTRS)

Information regarding the availability of LANDSAT imagery processed and input to the data files by the NASA Data Processing Facility is published on a monthly basis. The U.S. Standard Catalog includes imagery covering the continental United States, Alaska and Hawaii. The Non-U.S. Standard Catalog identifies all the remaining coverage. Sections 1 and 2 describe the contents and format for the catalogs and the associated microfilm. Section 3 provides a cross-reference defining the beginning and ending dates for LANDSAT cycles. Sections 4 and 5 cover LANDSAT-1 and LANDSAT-2 coverage, respectively.

1975-01-01

153

Using overlays to improve network security  

NASA Astrophysics Data System (ADS)

As we increase our dependency upon networked communication, the incentive to compromise and degrade network performance increases for those who wish to disrupt the flow of information. Attacks that lead to such compromise and degradation can come in a variety of forms, including distributed denial of service (DDoS) attacks, cutting wires, jamming transmissions, and monitoring/eavesdropping. Users can protect themselves from monitoring by applying cryptographic techniques, and the recent work has explored developing networks that react to DDoS attacks by locating the source(s) of the attack. However, there has been little work that addresses preventing the other kinds of attacks as opposed to reacting to them. Here, we discuss how network overlays can be used to complicate the job of an attacker that wishes to prevent communication. To amplify our point, we focus briefly on a study of preventing DDoS attacks by using overlays.

Keromytis, Angelos D.; Misra, Vishal; Rubenstein, Daniel

2002-07-01

154

Non-linear methods for overlay control  

NASA Astrophysics Data System (ADS)

Overlay requirements for DRAM devices are decreasing faster than anticipated. With current methods overlay becomes ever harder to control and therefore novel techniques are needed. This paper will present an alignment based method to address this issue. The use and impact of several non-linear alignment models will be presented. Issues here include the number of alignment marks to use and how to distribute them over the wafer in order to minimize the throughput impact while at the same time providing maximum wafer coverage. Integrating this method into a R2R environment strongly depends on the stability of the process. Advantages and disadvantages of the method will be presented as well as experimental results. Finally some comments will be given on the need and feasibility of wafer by wafer corrections.

Kupers, Michiel; Choi, Dongsub; Habets, Boris; Simons, Geert; Wallerbos, Erik

2007-03-01

155

The Case for Wireless Overlay Networks  

Microsoft Academic Search

Wireless data services, other than those for electronic mail or paging, have thus far been more of a promise than a success.\\u000a We believe that future mobile information systems must be built upon heterogeneous wireless overlay networks, extending traditional wired and internetworked processing “islands” to hosts on the move over coverage areas ranging from\\u000a in-room, in-building, campus, metropolitan, and wide-areas.

Randy H. Katz; Eric A. Brewer

156

Understanding Multiple-tree-based Overlay Multicast  

Microsoft Academic Search

ABSTRACT The two main sources of impairment,in overlay multicast systems are packet losses and node churn. Yet, little is known about their effects on the data distribution performance. In this paper we develop an analytical model,of a large class of peer-to-peer streaming architectures based on decomposition,and non-linear recurrence relations. We analyze the stability properties of these systems using fixed-point analysis.

Gy Orgy D An; Vikt Oria Fodor

157

Vertical Handoffs in Wireless Overlay Networks  

Microsoft Academic Search

Abstract: We present extensions to a traditional cellular [Ses95] handoff system to handle the simultaneous operation of multiplewireless network interfaces. This new system allows mobile users to roam in a "Wireless Overlay Network"structure consisting of room-size, building-size, and wide-area data networks. In this structure, the user can connectto the wired network through multiple wireless subnets, and offers the best possible

Mark Stemm; Randy H. Katz

1998-01-01

158

Proposal of Constructing PKI on Overlay Network  

Microsoft Academic Search

In this paper, we present the design of foundation PKI (fPKI), a PKI system constructed on an overlay network for an open source community. fPKI can provide an alter- native PKI system to the current server-client PKI system. The Certificate Authority (CA) system of the fPKI is com- posed of the reputation of each committer, which has been assessed by

Yukio Okada; Hiroaki Hazeyama; Youki Kadobayashi

2007-01-01

159

Floodplain Delineation Using Landsat-1 Data.  

National Technical Information Service (NTIS)

A continuous floodplain boundary was drawn on the basis of interpretation of the computer classification of selected Landsat-1 digital MSS data. Within the agricultural and developed portion of the study area, this floodplain correlated quite favorably wi...

D. L. Henninger M. L. Stauffer G. W. Petersen G. J. McMurtry

1975-01-01

160

LANDSAT-4 Scientific Characterization: Early Results Symposium  

NASA Technical Reports Server (NTRS)

Radiometric calibration, geometric accuracy, spatial and spectral resolution, and image quality are examined for the thematic mapper and the multispectral band scanner on LANDSAT 4. Sensor performance is evaluated.

1983-01-01

161

Landsat: A Space Age Water Gauge  

NASA Video Gallery

Water specialists Rick Allen, Bill Kramber and Tony Morse use Landsat thermal band data to measure the amount of water evaporating from the soil and transpiring from plants? leaves ? a process call...

162

Landsat and Apollo: The Forgotten Legacy  

Microsoft Academic Search

This paper demonstrates that Landsat was fundamentally a result of the Apollo Program. The U.S. Geological Survey's EROS proposal of 1966, which eventually led to Landsat, was stimulated largely by the demonstrated utility of 1100 orbital photographs from the Gemini missions, Gemini being solely preparation for Apollo. In addition, Earth-oriented remote sensing research sponsored by NASA in the mid-1 960s,

Paul D. Lowman

1999-01-01

163

New low-viscosity overlay medium for viral plaque assays  

PubMed Central

Background Plaque assays in cell culture monolayers under solid or semisolid overlay media are commonly used for quantification of viruses and antiviral substances. To overcome the pitfalls of known overlays, we tested suspensions of microcrystalline cellulose Avicel RC/CL™ as overlay media in the plaque and plaque-inhibition assay of influenza viruses. Results Significantly larger plaques were formed under Avicel-containing media, as compared to agar and methylcellulose (MC) overlay media. The plaque size increased with decreasing Avicel concentration, but even very diluted Avicel overlays (0.3%) ensured formation of localized plaques. Due to their low viscosity, Avicel overlays were easier to use than methylcellulose overlays, especially in the 96-well culture plates. Furthermore, Avicel overlay could be applied without prior removal of the virus inoculum thus facilitating the assay and reducing chances of cross-contamination. Using neuraminidase inhibitor oseltamivir carboxylate, we demonstrated applicability of the Avicel-based plaque reduction assay for testing of antiviral substances. Conclusion Plaque assay under Avicel-containing overlay media is easier, faster and more sensitive than assays under agar- and methylcellulose overlays. The assay can be readily performed in a 96-well plate format and seems particularly suitable for high-throughput virus titrations, serological studies and experiments on viral drug sensitivity. It may also facilitate work with highly pathogenic agents performed under hampered conditions of bio-safety labs.

Matrosovich, Mikhail; Matrosovich, Tatyana; Garten, Wolfgang; Klenk, Hans-Dieter

2006-01-01

164

Overlay target design and evaluation for SADP process  

NASA Astrophysics Data System (ADS)

Overlay performance has been a critical factor for advanced semiconductor manufacturing for years. Over time these requirements become more stringent as design rules shrink. Overlay mark design and selection are the first two steps of overlay control, and it is known that different overlay mark designs will have different responses to process conditions. An overlay mark optimized for traditional process might not be suitable for SADP (self-aligned double patterning) technology due to changes in lithography and etching process conditions. For instance, the traditional BIB (box-in-box) target defined by the core mask becomes a template structure in SADP flow, the pitch and cycle of the overlay mark is further changed after spacer formation and core film removal hence the mark recognition and robustness have been challenging for the subsequent process layers. The comprehensive study on the methodology of overlay mark design and selection is still not available for SADP process. In this paper, various types of overlay marks were designed to comply with the SADP process to get rid of the weaknesses of traditional targets. TMU (total measurement uncertainty) performance was adopted to determine the optimal overlay marks for meeting production overlay control requirements in SADP process flow. The results have suggested the segmented marks outperform to non-segmented marks on image contrast as well as TMU.

Yeh, C. W.; Huang, Chao-Tien H.; Lin, Kengchi; Huang, C. H.; Yang, Elvis; Yang, T. H.; Chen, K. C.; Lu, Chih-Yuan

2012-03-01

165

LANDSAT: US Standard Catalog, 1-31 December 1976. [LANDSAT imagery for December 1976  

NASA Technical Reports Server (NTRS)

The U.S. Standard Catalog lists U.S. imagery acquired by LANDSAT 1 and LANDSAT 2 which has been processed and input to the data files during the referenced month. Data, such as date acquired, cloud cover and image quality are given for each scene. The microfilm roll and frame on which the scene may be found are also given.

1976-01-01

166

LANDSAT 2 cumulative US standard catalog. [LANDSAT imagery for January 1976  

NASA Technical Reports Server (NTRS)

The U.S. Standard Catalog lists U.S. imagery acquired by LANDSAT 1 and LANDSAT 2 which has been processed and input to the data files during the referenced month. Data, such as date acquired, cloud cover and image quality, are given for each scene. The microfilm roll and frame on which the scene may be found is also given.

1977-01-01

167

Molecular Dynamics study of Pb overlayer on Cu(100)  

NASA Technical Reports Server (NTRS)

Isothermal-isobaric Molecular Dynamics (MD) simulation of a submonolayer Pb film in c(2x2) ordered structure adsorbed on a Cu(100) substrate showed retention of order to high T. The Embedded Atom Method (EAM) calculated the energy of atoms of overlayer and substrate. The time-averaged squared modulus of the two dimensional structure factor for the Pb overlayer measured the order of the overlayer. The results are for increasing T only, and require verification by simulated cooling.

Karimi, M.; Tibbits, P.; Ila, D.; Dalins, I.; Vidali, G.

1991-01-01

168

Nyiragongo Volcano, Congo, Map View with Lava, Landsat / ASTER / SRTM  

NASA Technical Reports Server (NTRS)

The Nyiragongo volcano in the Congo erupted on January 17, 2002, and subsequently sent streams of lava into the city of Goma on the north shore of Lake Kivu. More than 100 people were killed, more than 12,000 homes were destroyed, and hundreds of thousands were forced to flee the broader community of nearly half a million people. This Landsat satellite image shows the volcano (right of center), the city of Goma, and surrounding terrain. Image data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA's Terra satellite were used to supply a partial map of the recent lava flows (red overlay), including a complete mapping of their intrusion into Goma as of January 28, 2002. Lava is also apparent within the volcanic crater and at a few other locations. Thick (but broken) cloud cover during the ASTER image acquisition prevented a complete mapping of the lava distribution, but future image acquisitions should complete the mapping.

Goma has a light pink speckled appearance along the shore of Lake Kivu. The city airport parallels, and is just right (east) of, the larger lava flow. Nyiragongo peaks at about 3,470 meters (11,380 feet) elevation and reaches almost exactly 2,000 meters (6,560 feet) above Lake Kivu. The shorter but much broader Nyamuragira volcano appears in the upper left.

Goma, Lake Kivu, Nyiragongo, Nyamuragira and other nearby volcanoes sit within the East African Rift Valley, a zone where tectonic processes are cracking, stretching, and lowering the Earth's crust. Volcanic activity is common here, and older but geologically recent lava flows (magenta in this depiction) are particularly apparent on the flanks of the Nyamuragira volcano.

The Landsat image used here was acquired on December 11, 2001, about a month before the eruption, and shows an unusually cloud-free view of this tropical terrain. Minor clouds and their shadows were digitally removed to clarify the view and topographic shading derived from the SRTM elevation model was added to the Landsat image. Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and substantially helps in analyzing the large and growing Landsat image archive. This Landsat 7 Thematic Mapper image was provided to the SRTM and ASTER projects by the United States Geological Survey, Earth Resources Observation Systems (EROS) Data Center, Sioux Falls, S.D.

With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) will image Earth for several years to map and monitor the changing surface of our planet. ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy,Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products. ASTER is providing scientists in numerous disciplines with critical information for surface mapping and monitoring dynamic conditions and temporal change.

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter(approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's

2002-01-01

169

Scanner grid recipe creation improvement for tighter overlay specifications  

NASA Astrophysics Data System (ADS)

Overlay specifications are tightening with each lithography technology node. As a result, there is a need to improve overlay control methodologies to make them more robust and less time- or effort-consuming, but without any compromise in quality. Two concepts aimed at improving the creation of scanner grid recipes in order to meet evertightening overlay specifications are proposed in this article. Simulations will prove that these concepts can achieve both goals, namely improving overlay control performance and reducing the time and effort required to do so. While more studies are needed to fine-tune the parameters to employ, the trends presented in this paper clearly show the benefits.

Cotte, Eric; Kathiresan, Hariharasudhan; Ruhm, Matthias; Schulz, Bernd; Schulze, Uwe

2013-10-01

170

Landsat-7 Mission and Early Results  

NASA Technical Reports Server (NTRS)

The Landsat-7 mission has the goal of acquiring annual data sets of reflective band digital imagery of the landmass of the Earth at a spatial resolution of 30 meters for a period of five years using the Enhanced Thematic Mapper Plus (ETM+) imager on the Landsat-7 satellite. The satellite was launched on April 15, 1999. The mission builds on the 27-year continuous archive of thematic images of the Earth from previous Landsat satellites. This paper will describe the ETM+ instrument, the spacecraft, and the ground processing system in place to accomplish the mission. Results from the first few months in orbit will be given, with emphasis on performance parameters that affect image quality, quantity, and availability. There will also be a discussion of the Landsat Data Policy and the user interface designed to make contents of the archive readily available, expedite ordering, and distribute the data quickly. Landsat-7, established by a Presidential Directive and a Public Law, is a joint program of the National Aeronautics and Space Administration (NASA) Earth Science Enterprise and the United States Geological Survey (USGS) Earth Resources Observing System (EROS) Data Center.

Dolan, S. Kenneth; Sabelhaus, Phillip A.; Williams, Darrel L.; Irons, James R.; Barker, John L.; Markham, Brian L.; Bolek, Joseph T.; Scott, Steven S.; Thompson, R. J.; Rapp, Jeffrey J.

1999-01-01

171

Spatial and Spectral Simulation of LANDSAT Images of Agricultural Areas.  

National Technical Information Service (NTIS)

A LANDSAT scene simulation capability was developed to study the effects of small fields and misregistration on LANDSAT-based crop proportion estimation procedures. The simulation employs a pattern of ground polygons each with a crop ID, planting date, an...

W. F. Pont

1982-01-01

172

Real cell overlay measurement through design based metrology  

NASA Astrophysics Data System (ADS)

Until recent device nodes, lithography has been struggling to improve its resolution limit. Even though next generation lithography technology is now facing various difficulties, several innovative resolution enhancement technologies, based on 193nm wavelength, were introduced and implemented to keep the trend of device scaling. Scanner makers keep developing state-of-the-art exposure system which guarantees higher productivity and meets a more aggressive overlay specification. "The scaling reduction of the overlay error has been a simple matter of the capability of exposure tools. However, it is clear that the scanner contributions may no longer be the majority component in total overlay performance. The ability to control correctable overlay components is paramount to achieve the desired performance.(2)" In a manufacturing fab, the overlay error, determined by a conventional overlay measurement: by using an overlay mark based on IBO and DBO, often does not represent the physical placement error in the cell area of a memory device. The mismatch may arise from the size or pitch difference between the overlay mark and the cell pattern. Pattern distortion, caused by etching or CMP, also can be a source of the mismatch. Therefore, the requirement of a direct overlay measurement in the cell pattern gradually increases in the manufacturing field, and also in the development level. In order to overcome the mismatch between conventional overlay measurement and the real placement error of layer to layer in the cell area of a memory device, we suggest an alternative overlay measurement method utilizing by design, based metrology tool. A basic concept of this method is shown in figure1. A CD-SEM measurement of the overlay error between layer 1 and 2 could be the ideal method but it takes too long time to extract a lot of data from wafer level. An E-beam based DBM tool provides high speed to cover the whole wafer with high repeatability. It is enabled by using the design as a reference for overlay measurement and a high speed scan system. In this paper, we have demonstrated that direct overlay measurement in the cell area can distinguish the mismatch exactly, instead of using overlay mark. This experiment was carried out for several critical layer in DRAM and Flash memory, using DBM(Design Based Metrology) tool, NGR2170™.

Yoo, Gyun; Kim, Jungchan; Park, Chanha; Lee, Taehyeong; Ji, Sunkeun; Jo, Gyoyeon; Yang, Hyunjo; Yim, Donggyu; Yamamoto, Masahiro; Maruyama, Kotaro; Park, Byungjun

2014-04-01

173

Synthetic aperture radar/LANDSAT MSS image registration  

NASA Technical Reports Server (NTRS)

Algorithms and procedures necessary to merge aircraft synthetic aperture radar (SAR) and LANDSAT multispectral scanner (MSS) imagery were determined. The design of a SAR/LANDSAT data merging system was developed. Aircraft SAR images were registered to the corresponding LANDSAT MSS scenes and were the subject of experimental investigations. Results indicate that the registration of SAR imagery with LANDSAT MSS imagery is feasible from a technical viewpoint, and useful from an information-content viewpoint.

Maurer, H. E. (editor); Oberholtzer, J. D. (editor); Anuta, P. E. (editor)

1979-01-01

174

Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS)  

NASA Technical Reports Server (NTRS)

The Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) project is creating a record of forest disturbance and regrowth for North America from the Landsat satellite record, in support of the carbon modeling activities. LEDAPS relies on the decadal Landsat GeoCover data set supplemented by dense image time series for selected locations. Imagery is first atmospherically corrected to surface reflectance, and then change detection algorithms are used to extract disturbance area, type, and frequency. Reuse of the MODIS Land processing system (MODAPS) architecture allows rapid throughput of over 2200 MSS, TM, and ETM+ scenes. Initial ("Beta") surface reflectance products are currently available for testing, and initial continental disturbance products will be available by the middle of 2006.

Masek, Jeffrey G.

2006-01-01

175

Status of the Landsat Data Continuity Mission  

NASA Technical Reports Server (NTRS)

Efforts to begin implementing a successor mission to Landsat 7, called the Landsat Data Continuity Mission (LDCM), suffered a set back in 2003. NASA and the Department of Interior (DOI)/U.S. Geological Survey (USGS) currently manage the Landsat Program as an interagency partnership. The two agencies had planned to purchase data meeting LDCM specifications from a privately owned and commercially operated satellite system beginning in March, 2007. This approach represented a departure from the traditional procurement of a government owned and operated satellite system. NASA, however, cancelled a Request-for-Proposals (RFP) for providing the required data after an evaluation of proposals received from private industry. NASA concluded that the proposals failed to meet a key objective and expectation of the RFP, namely, to form a fair and equitable partnership between the Government and private industry. Alternative strategies for implementing an LDCM are now under consideration. The Executive Office of the President formed an interagency working group on the LDCM following the RFP cancellation. The working group is considering other options for implementing a successor system to Landsat 7 consistent with the Land Remote Sensing Policy Act of 1992 (Public Law 102-555). This Act lists four management options for consideration: 1) private sector funding and management; 2) an international consortium; 3) funding and management by the U.S. Government; and 4) a cooperative effort between the US. Government and the private sector. The working group is currently attempting to minimize the risk of a Landsat data gap through development of a strategy that leads to a Landsat 7 successor mission. The selected strategy and the status of the mission will be presented at the Symposium.

Irons, James R.; Ochs, William R.

2004-01-01

176

Crop Classification with a Landsat\\/Radar Sensor Combination  

Microsoft Academic Search

A combined Landsat\\/radar approach to classification of remotely sensed data, with emphasis on crops, was undertaken. Radar data were obtained by microwave radar spectrometers over fields near Eudora, Kansas and Landsat image data were obtained for the same test site. After Landsat digital images were registered and test-cells extracted, a comparable set of radar image pixels were simulated to match

Robert Y. Li; Fawwaz T. Ulaby; Ronald J. Eyton

1980-01-01

177

A study of atmospheric diffusion from the LANDSAT imagery  

Microsoft Academic Search

Detailed analyses of the LANDSAT multispectral scanner (MSS) data of the smoke plumes that originated in eastern Cabo Frio (22° 59'S 42° 02'W) and crossed over into the Atlantic ocean are presented to illustrate how high-resolution LANDSAT imagery can aid meteorologists in evaluating specific air pollution events. The eleven LANDSAT images selected are for different months and years. Conventional interpretation

Y. Viswanadham; J. A. Torsani

1982-01-01

178

LANDSAT-D data format control book. Volume 5: (Payload)  

NASA Technical Reports Server (NTRS)

The LANDSAT-D flight segment payload is the thematic mapper and the multispectral scanner. Narrative and visual descriptions of the LANDSAT-D payload data handling hardware and data flow paths from the sensing instruments through to the GSFC LANDSAT-D data management system are provided. Key subsystems are examined.

Andrew, H.

1981-01-01

179

Residual stresses in weld overlay tubes: A finite element study  

Microsoft Academic Search

Residual stresses and strains in a tube with circumferential weld overlay were analyzed by the finite element (FE) method. The objective of this work was to develop and verify a FE model, to determine the magnitude and distribution of residual stresses in the weld overlay tube, and to evaluate the significance of two contributing factors to residual stress: (1) difference

B. Taljat; T. Zacharia; X. L. Wang; J. R. Keiser; Z. Feng; M. J. Jirinec

1997-01-01

180

Calculating the Area of Overlaid Polygons Without Constructing the Overlay  

Microsoft Academic Search

An algorithm and implementation for calculating the areas of overlaid polygons without calculating the overlay itself, is presented. is useful when the sole purpose of overlaying two maps is to find some mass property of the resulting polygons, or for an areal interpolation of data from one map to the other. Finding the areas of all the output polygons is

William Randolph Franklin; Venkateshkumar Sivaswami; David Sun; Mohan Kankanhalli; Chandrasekhar Narayanaswami

1994-01-01

181

Measurement of residual stress in the weld overlay piping components  

Microsoft Academic Search

In general industry, especially in the nuclear industry, welding overlay repair is an important repair method mainly used to rebuild piping systems suffering from intergranular stress-corrosion cracking (IGSCC).The pipe surface is mechanically ground to obtain a smooth surface after the welding overlay repair. A better understanding of the effect of repair and grinding processes on the residual stresses at the

H.-J. Yen; M. C. C. Lin

1995-01-01

182

Residual stress measurement in 304 stainless steel weld overlay pipes  

Microsoft Academic Search

Welding overlay repair (WOR) is commonly employed to rebuild piping systems suffering from intergranular stress corrosion cracking (IGSCC). To understand the effects of this repair, it is necessary to investigate the distribution of residual stresses in the welding pipe. The overlay welding technique must induce compressive residual stress at the inner surface of the welded pipe to prevent IGSCC. To

Hung-Ju Yen; Mark Ching-Cheng Lin; Lih-Jin Chen

1996-01-01

183

Thermal stress in EML rail-conductor overlays  

Microsoft Academic Search

In an electromagnetic (EM) railgun, a thin, unbonded overlay on the rail conductor develops residual strains as evident from its post-shot curvature. Heating due to the transient EM field and a large thermal gradient due to deposition of a molten layer of armature material contribute to the straining of the overlay. In this paper, the authors solved the one-dimensional coupled

S. Satapathy; C. Persad

2001-01-01

184

A map overlay error model based on boundary geometry  

USGS Publications Warehouse

An error model for quantifying the magnitudes and variability of errors generated in the areas of polygons during spatial overlay of vector geographic information system layers is presented. Numerical simulation of polygon boundary displacements was used to propagate coordinate errors to spatial overlays. The model departs from most previous error models in that it incorporates spatial dependence of coordinate errors at the scale of the boundary segment. It can be readily adapted to match the scale of error-boundary interactions responsible for error generation on a given overlay. The area of error generated by overlay depends on the sinuosity of polygon boundaries, as well as the magnitude of the coordinate errors on the input layers. Asymmetry in boundary shape has relatively little effect on error generation. Overlay errors are affected by real differences in boundary positions on the input layers, as well as errors in the boundary positions. Real differences between input layers tend to compensate for much of the error generated by coordinate errors. Thus, the area of change measured on an overlay layer produced by the XOR overlay operation will be more accurate if the area of real change depicted on the overlay is large. The model presented here considers these interactions, making it especially useful for estimating errors studies of landscape change over time. ?? 2005 The Ohio State University.

Gaeuman, D.; Symanzik, J.; Schmidt, J. C.

2005-01-01

185

Design of overlays based on pavement condition, roughness, and deflections  

NASA Astrophysics Data System (ADS)

The development and use of a pavement maintenance rating system and the development of two procedures for designing the thickness of overlays are summarized. It is demonstrated that objective rating systems can be used to prioritize pavements scheduled for resurfacing and that the procedures for overlay design based on the existing pavement structure and on traffic loadings are practical.

McGhee, K. H.

1982-01-01

186

Landsat classification of coastal wetlands in Texas  

NASA Technical Reports Server (NTRS)

Through a multiagency study of Landsat imagery applications, an analysis of Texas coastal wetlands shows that five Level III categories of wetlands can be delineated using image interpretation: topographically low marshes, topographically high marshes, tidal flats, sea grass and algal flats, and vegetated dredged material. Image interpretation involves optical enlargement of 1:1,000,000 scale, Landsat transparencies to a scale of 1:125,000 and mapping on a stable film base. Digital classification procedures, resulting in 1:24,000 scale line printer maps as output, require several iterations to display welands effectively. Accuracies of 65% were achieved for all wetland categories combined.

Finley, R. J.; Mcculloch, S.; Harwood, P.

1981-01-01

187

The LANDSAT/global positioning system project  

NASA Technical Reports Server (NTRS)

A GPSPAC/LANDSAT-D Interface (GLI) Ground Support System was built to validate the performance and to calibrate the accuracy of the experimental navigation package, GPSPAC, flown on the LANDSAT-4 and 5 spacecraft. Although the GLI system operated successfully to give the orbit information needed to validate the GPSPAC, it also detected two anomalies: one is characteristic of the GLI system and the other is characteristic of the pre-operational phase of GPS. Several methods were applied to resolve or reduce the anomalies. This paper presents a description of the problems, the methods applied to resolve or reduce them, and the results.

Wood, Terri

1988-01-01

188

Urban area update procedures using Landsat data  

NASA Technical Reports Server (NTRS)

Landsat digital enhancements and classification maps are shown to be useful for updating the urban expansion of standard metropolitan statistical areas on a macro scale. Automated procedures for detecting nonurban to urban land coverage change using multitemporal Landsat data are investigated for five metropolitan areas, showing an overall delineation similar to that obtained from large scale aerial photography. The evaluated change detection procedures include image differencing, principal component transformation prior to differencing, and post classification comparison. Results show that image differencing techniques in MSS band 5 provide the most accurate land cover change detections.

Toll, D. L.; Royal, J. A.; Davis, J. B.

1981-01-01

189

USGS Releases Landsat Orthorectified State Mosaics  

USGS Publications Warehouse

The U.S. Geological Survey (USGS) National Remote Sensing Data Archive, located at the USGS Center for Earth Resources Observation and Science (EROS) in Sioux Falls, South Dakota, maintains the Landsat orthorectified data archive. Within the archive are Landsat Enhanced Thematic Mapper Plus (ETM+) data that have been pansharpened and orthorectified by the Earth Satellite Corporation. This imagery has acquisition dates ranging from 1999 to 2001 and was created to provide users with access to quality-screened, high-resolution satellite images with global coverage over the Earth's landmasses.

Geological Survey (U.S.)

2005-01-01

190

Wheat productivity estimates using LANDSAT data  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. Large area LANDSAT yield estimates were generated. These results were compared with estimates computed using a meteorological yield model (CCEA). Both of these estimates were compared with Kansas Crop and Livestock Reporting Service (KCLRS) estimates of yield, in an attempt to assess the relative and absolute accuracy of the LANDSAT and CCEA estimates. Results were inconclusive. A large area direct wheat prediction procedure was implemented. Initial results have produced a wheat production estimate comparable with the KCLRS estimate.

Nalepka, R. F.; Colwell, J. E. (principal investigators); Rice, D. P.; Bresnahan, P. A.

1977-01-01

191

Study of atmospheric diffusion using LANDSAT  

NASA Technical Reports Server (NTRS)

The parameters of diffusion patterns of atmospheric pollutants under different conditions were investigated for use in the Gaussian model for calculation of pollution concentration. Value for the divergence pattern of concentration distribution along the Y axis were determined using LANDSAT images. Multispectral scanner images of a point source plume having known characteristics, wind and temperature data, and cloud cover and solar elevation data provided by LANDSAT, were analyzed using the 1-100 system for image analysis. These measured values are compared with pollution transport as predicted by the Pasquill-Gifford, Juelich, and Hoegstroem atmospheric models.

Torsani, J. A.; Viswanadham, Y.

1982-01-01

192

Monitoring of a rice field using landsat-5 TM and landsat-7 ETM+ data  

NASA Astrophysics Data System (ADS)

Through the research on the application of the multi temporal data acquired with Landsat-5 TM and Landsat-7 ETM+ to monitoring of rice field the following features are clarified Two vegetation indices NDVI (Normalized Difference Vegetation Index) and EVI (Extended Vegetation Index) obtained from Landsat-5 TM data of 7 July 2000 and that from Landsat-7 ETM+ data of 6 July 2000 show almost the same feature proving the validity of calibration of both sensors. NDVI computed from satellite data increases corresponding to the growth of rice plants until the flowering stage while EVI further continues to increase until the fructification stage. The vegetation indices computed from the in situ survey data with a portable multispectral radiometer do not coincide with those computed from satellite data. This is because that the reflectance of the background such as soil and water is included in the satellite data.

Oguro, Y.; Suga, Y.; Takeuchi, S.; Ogawa, H.; Tsuchiya, K.

2003-12-01

193

LANDSAT-1 and LANDSAT-2 flight evaluation report, 23 April - 23 July 1976  

NASA Technical Reports Server (NTRS)

LANDSAT 1 and 2 operations were described, giving detailed charts and tables of their performances since 1972. Orbital parameters, attitude control subsystem, telemetry subsystem, orbit adjust subsystem, and magnetic moment compensating assembly were some of the main parameters discussed.

1976-01-01

194

A constitutive model for an overlay coating  

NASA Technical Reports Server (NTRS)

Coatings are frequently applied to gas turbine blades and vanes to provide protection against oxidation and corrosion. The results of an experimental and analytical study to develop a constitutive model for an overlay coating is presented. Specimens were machined from a hot isostatically pressed billet of PWA 286. The tests consisted of isothermal stress relaxation cycles with monotonically increasing maximum strain and were conducted at various temperatures. The results were used to calculate the constants for various constitutive models, including the classical, the Walker isotropic, a simplified Walker, and Stowell models. A computerized regression analysis was used to calculate model constants from the data. The best fit was obtained for the Walker model, with the simplified Walker and classical models close behind.

Nissley, D. M.; Swanson, G. A.

1988-01-01

195

Performance of the GPS package on Landsat-5  

NASA Technical Reports Server (NTRS)

The Landsat-5 spacecraft, launched in March 1984, carries an experimental Global Positioning System Package (GPSPAC) as did Landsat-4 in 1982. The primary objective of this experiment was to characterize and improve the performance of GPSPAC as an onboard navigation tool. In order to validate the accuracy of GPSPAC orbit solutions, definitive Landsat-5 ephemerides, derived from ground based tracking data, were generated and compared with GPSPAC estimates. This paper presents the results of such analysis as well as a summary of GPSPAC operation on Landsat-5. A description of the Landsat-5 spacecraft, GPSPAC and its navigation algorithms are also included.

Heuberger, H.

1984-01-01

196

Irradiance-based cross-calibration of Landsat5 and Landsat7 Thematic Mapper sensors  

Microsoft Academic Search

On 2 June 1999 Landsat-5 and Landsat-7 passed over north-central Nebraska collecting Thematic Mapper (TM) data for essentially the same spatial location, with an acquisition time differing by less than 20 min. At the Niobrara Nature Preserve, Nebraska site, two multifilter rotating shadowband radiometers (MFRSRs), a Cimel sunphotometer, a Microtops sunphotometer, and an ASD-FR spectroradiometer were used to take ground-based

S. E. Black; D. L. Helder; S. J. Schiller

2003-01-01

197

LANDSAT-D Mission System Industry Briefing  

NASA Technical Reports Server (NTRS)

Viewgraphs and photographs depict the scope and purpose of the LANDSAT 4 mission as well as all satellite systems. The components and major functions of the flight and ground segments, operational support, communication links, and the hardware and interfaces for processing MSS and TM images are covered.

1982-01-01

198

BOREAS Landsat MSS Imagery: Digital Counts  

NASA Technical Reports Server (NTRS)

The Boreal Ecosystem-Atmospheric Study (BOREAS) Staff Science Satellite Data Acquisition Program focused on providing the research teams with the remotely sensed satellite data products they needed to compare and spatially extend point results. The Earth Resources Technology Satellite (ERTS) Program launched the first of a series of satellites (ERTS-1) in 1972. Part of the NASA Earth Resources Survey Program, the ERTS Program and the ERTS satellites were later renamed Landsat to better represent the civil satellite program's prime emphasis on remote sensing of land resources. Landsat satellites 1 through 5 carry the Multispectral Scanner (MSS) sensor. Canada for Remote Sensing (CCRS) and BOREAS personnel gathered a set of MSS images of the BOREAS region from Landsat satellites 1, 2, 4, and 5 covering the dates of 21 Aug 1972 to 05 Sep 1988. The data are provided in binary image format files of various formats. The Landsat MSS imagery is available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

Hall, Forrest G. (Editor); Nickeson, Jaime (Editor); Strub, Richard; Newcomer, Jeffrey A.

2000-01-01

199

Landsat non-US standard catalog  

NASA Technical Reports Server (NTRS)

The Non-U.S. Standard Catalog lists Non-U.S. imagery acquired by Landsat 1 and 2 which was processed and input to the data files during the referenced month. Data, such as date acquired, cloud cover and image quality are given for each scene. The microfilm roll and frame on which the scene may be found are also given.

1975-01-01

200

LANDSAT activities in the Republic of Zaire  

NASA Technical Reports Server (NTRS)

An overview of the LANDSAT data utilization program of the Republic of Zaire is presented. The program emphasizes topics of economic significance to the national development program of Zaire: (1) agricultural land use capability analysis, including evaluation of the effects of large-scale burnings; (2) mineral resources evaluation; and (3) production of mapping materials for poorly covered regions.

Ilunga, S.

1975-01-01

201

The Landsat Data Purchase and ESAD  

NASA Technical Reports Server (NTRS)

The Earth Science Applications Directorate (ESAD) purchases satellite imagery for The Scientific Data Purchase (SDP) Project. SDP allows a variety of customers in turn to purchase Landsat, IKONOS, and other data. The SDP customer base includes includes private companies, universities, and government agencies. SDP customers are required to register and receive clearance.

Policelli, Fritz; Fletcher, Rose

2001-01-01

202

Utilization of LANDSAT images in cartography  

NASA Technical Reports Server (NTRS)

The use of multispectral imagery obtained from LANDSAT for mapping purposes is discussed with emphasis on geometric rectification, image resolution, and systematic topographic mapping. A method is given for constructing 1:250,000 scale maps. The limitations for satellite cartography are examined.

Dejesusparada, N. (principal investigator); Alburquerque, P. C. G.

1981-01-01

203

Software for Viewing Landsat Mosaic Images  

NASA Technical Reports Server (NTRS)

A Windows-based computer program has been written to enable novice users (especially educators and students) to view images of large areas of the Earth (e.g., the continental United States) generated from image data acquired in the Landsat observations performed circa the year 1990. The large-area images are constructed as mosaics from the original Landsat images, which were acquired in several wavelength bands and each of which spans an area (in effect, one tile of a mosaic) of approx. 5 in latitude by approx. 6 deg in longitude. Whereas the original Landsat data are registered on a universal transverse Mercator (UTM) grid, the program converts the UTM coordinates of a mouse pointer in the image to latitude and longitude, which are continuously updated and displayed as the pointer is moved. The mosaic image currently on display can be exported as a Windows bit-map file. Other images (e.g., of state boundaries or interstate highways) can be overlaid on Landsat mosaics. The program interacts with the user via standard toolbar, keyboard, and mouse user interfaces. The program is supplied on a compact disk along with tutorial and educational information.

2002-01-01

204

Software for Viewing Landsat Mosaic Images  

NASA Technical Reports Server (NTRS)

A Windows-based computer program has been written to enable novice users (especially educators and students) to view images of large areas of the Earth (e.g., the continental United States) generated from image data acquired in the Landsat observations performed circa the year 1990. The large-area images are constructed as mosaics from the original Landsat images, which were acquired in several wavelength bands and each of which spans an area (in effect, one tile of a mosaic) of 5 in latitude by approximately equal to 6 degrees in longitude. Whereas the original Landsat data are registered on a universal transverse Mercator (UTM) grid, the program converts the UTM coordinates of a mouse pointer in the image to latitude and longitude, which are continuously updated and displayed as the pointer is moved. The mosaic image currently on display can be exported as a Windows bit-map file. Other images (e.g., of state boundaries or interstate highways) can be overlaid on Landsat mosaics. The program interacts with the user via standard toolbar, keyboard, and mouse user interfaces. The program is supplied on a compact disk along with tutorial and educational information.

Watts, Jack; Farve, Catherine L.; Harvey, Craig

2002-01-01

205

LANDSAT D data processing facility study  

NASA Technical Reports Server (NTRS)

Mission planning of the LANDSAT D is discussed which will present several major advances in the spacecraft, sensor (Thematic Mapper), ground systems and overall system design. The system provides for two data links-direct satellite to ground, and via the Tracking and Data Relay Satellite.

1976-01-01

206

LANDSAT-4 to ground station interface description  

NASA Technical Reports Server (NTRS)

The LANDSAT 4 to ground station interface is described in detail. The radiometric specifications, internal calibration, sensor output format, and data processing constants for the multispectral scanner and the thematic mapper are discussed. The mission payload telemetry, onboard computer telemetry, and engineering telemetry formats are described. In addition, the telemetry time signals and the onboard clock resetting procedure are addressed.

1983-01-01

207

40 + Years of Earth Science: The Landsat Program  

NSDL National Science Digital Library

A variety of man-made objects have been sent into outer space for decades, and as a very large and distinguished group, they have sent back important data. NASA has been at the forefront of these efforts here in the United States, and the Landsat Program has certainly been quite successful since its inception in the early 1970s. This website provides a wealth of information on the Landsat Program, and visitors can learn about its work in remote sensing. Visitors can use the right-hand side of the page to learn about different Landsat missions ranging from the original Landsat all the way up to Landsat Seven, which was launched in 1999. Each section contains information on Landsat's orbit, its instruments, and its vital statistics. Finally, a "Did You Know" section provides some key facts about some of the accomplishments of the Landsat program.

2005-01-01

208

Nyiragongo volcano, Congo, Anaglyph, SRTM / Landsat  

NASA Technical Reports Server (NTRS)

The Nyiragongo volcano in the Congo erupted on January 17, 2002, and subsequently sent streams of lava into the city of Goma on the north shore of Lake Kivu. More than 100 people were killed, more than 12,000 homes were destroyed, and hundreds of thousands were forced to flee the broader community of nearly half a million people. This stereoscopic (anaglyph) visualization combines a Landsat satellite image and an elevation model from the Shuttle Radar Topography Mission (SRTM) to provide a view of the volcano, the city of Goma, and surrounding terrain.

Nyiragongo is the steep volcano to the lower right of center, Lake Kivu is at the bottom, and the city of Goma is located along the northeast shore (bottom center). Nyiragongo peaks at about 3,470 meters (11,380 feet) elevation and reaches almost exactly 2,000 meters (6,560 feet) above Lake Kivu. The shorter but broader Nyamuragira volcano appears to the upper left of Nyiragongo.

Goma, Lake Kivu, Nyiragongo, Nyamuragira and other nearby volcanoes sit within the East African Rift Valley, a zone where tectonic processes are cracking, stretching, and lowering the Earth's crust. The cliff at the top center of the image is the western edge of the rift. Volcanic activity is common in the rift, and older but geologically recent lava flows (dark in this depiction) are particularly apparent on the flanks of the Nyamuragira volcano.

This anaglyph was produced by first shading an elevation model from data acquired by the Shuttle Radar Topography Mission and blending it with a single band of a Landsat scene. The stereoscopic effect was then created by generating two differing perspectives, one for each eye. When viewed through special glasses, the result is a vertically exaggerated view of the Earth's surface in its full three dimensions. Anaglyph glasses cover the left eye with a red filter and the right eye with a blue filter.

The Landsat image used here was acquired on December 11, 2001, about a month before the eruption, and shows an unusually cloud-free view of this tropical terrain. Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and substantially helps in analyzing the large and growing Landsat image archive. This Landsat 7 Thematic Mapper image was provided to the SRTM project by the United States Geological Survey, Earth Resources Observation Systems (EROS) DataCenter, Sioux Falls, S.D.

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on February 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise,Washington, D.C.

Size: 43 by 62 kilometers (27 by 39 miles) Location: 1.5 degrees South latitude, 29.3 degrees East longitude Orientation: East-northeast at top Image Data: Landsat Band 4 (near infrared) combined with SRTM shaded relief Original Data Resolution: SRTM 1 arcsecond (30 meters or 98 feet), Landsat 30 meters (98 feet). Date Acquired: February 2000 (SRTM), December 11, 2001 (Landsat)

2002-01-01

209

Landsat Thematic Mapper Image Mosaic of Colorado  

USGS Publications Warehouse

The U.S. Geological Survey (USGS) Rocky Mountain Geographic Science Center (RMGSC) produced a seamless, cloud-minimized remotely-sensed image spanning the State of Colorado. Multiple orthorectified Landsat 5 Thematic Mapper (TM) scenes collected during 2006-2008 were spectrally normalized via reflectance transformation and linear regression based upon pseudo-invariant features (PIFS) following the removal of clouds. Individual Landsat scenes were then mosaicked to form a six-band image composite spanning the visible to shortwave infrared spectrum. This image mosaic, presented here, will also be used to create a conifer health classification for Colorado in Scientific Investigations Map 3103. An archive of past and current Landsat imagery exists and is available to the scientific community (http://glovis.usgs.gov/), but significant pre-processing was required to produce a statewide mosaic from this information. Much of the data contained perennial cloud cover that complicated analysis and classification efforts. Existing Landsat mosaic products, typically three band image composites, did not include the full suite of multispectral information necessary to produce this assessment, and were derived using data collected in 2001 or earlier. A six-band image mosaic covering Colorado was produced. This mosaic includes blue (band 1), green (band 2), red (band 3), near infrared (band 4), and shortwave infrared information (bands 5 and 7). The image composite shown here displays three of the Landsat bands (7, 4, and 2), which are sensitive to the shortwave infrared, near infrared, and green ranges of the electromagnetic spectrum. Vegetation appears green in this image, while water looks black, and unforested areas appear pink. The lines that may be visible in the on-screen version of the PDF are an artifact of the export methods used to create this file. The file should be viewed at 150 percent zoom or greater for optimum viewing.

Cole, Christopher J.; Noble, Suzanne M.; Blauer, Steven L.; Friesen, Beverly A.; Bauer, Mark A.

2010-01-01

210

Bayesian networks in overlay recipe optimization  

NASA Astrophysics Data System (ADS)

Currently, overlay measurements are characterized by "recipe", which defines both physical parameters such as focus, illumination et cetera, and also the software parameters such as algorithm to be used and regions of interest. Setting up these recipes requires both engineering time and wafer availability on an overlay tool, so reducing these requirements will result in higher tool productivity. One of the significant challenges to automating this process is that the parameters are highly and complexly correlated. At the same time, a high level of traceability and transparency is required in the recipe creation process, so a technique that maintains its decisions in terms of well defined physical parameters is desirable. Running time should be short, given the system (automatic recipe creation) is being implemented to reduce overheads. Finally, a failure of the system to determine acceptable parameters should be obvious, so a certainty metric is also desirable. The complex, nonlinear interactions make solution by an expert system difficult at best, especially in the verification of the resulting decision network. The transparency requirements tend to preclude classical neural networks and similar techniques. Genetic algorithms and other "global minimization" techniques require too much computational power (given system footprint and cost requirements). A Bayesian network, however, provides a solution to these requirements. Such a network, with appropriate priors, can be used during recipe creation / optimization not just to select a good set of parameters, but also to guide the direction of search, by evaluating the network state while only incomplete information is available. As a Bayesian network maintains an estimate of the probability distribution of nodal values, a maximum-entropy approach can be utilized to obtain a working recipe in a minimum or near-minimum number of steps. In this paper we discuss the potential use of a Bayesian network in such a capacity, reducing the amount of engineering intervention. We discuss the benefits of this approach, especially improved repeatability and traceability of the learning process, and quantification of uncertainty in decisions made. We also consider the problems associated with this approach, especially in detailed construction of network topology, validation of the Bayesian network and the recipes it generates, and issues arising from the integration of a Bayesian network with a complex multithreaded application; these primarily relate to maintaining Bayesian network and system architecture integrity.

Binns, Lewis A.; Reynolds, Greg; Rigden, Timothy C.; Watkins, Stephen; Soroka, Andrew

2005-05-01

211

Enumeration of bacteriophages by double agar overlay plaque assay.  

PubMed

The determination of the concentration of infectious phage particles is fundamental to many protocols in phage biology, genetics, and molecular biology. In this chapter the classical overlay protocol is described. PMID:19066811

Kropinski, Andrew M; Mazzocco, Amanda; Waddell, Thomas E; Lingohr, Erika; Johnson, Roger P

2009-01-01

212

Mask contribution to intra-field wafer overlay  

NASA Astrophysics Data System (ADS)

Shrinking wafer overlay budgets raise the importance of careful characterization and control of the contributing components, a trend accelerated by multi-patterning immersion lithography [1]. Traditionally, the mask contribution to wafer overlay has been estimated from measurement of a relatively small number of standard targets. There are a number of studies on test masks and standard targets of the impact of mask registration on wafer overlay [2],[3]. In this paper, we show the value of a more comprehensive characterization of mask registration on a product mask, across a wide range of spatial frequencies and patterns. The mask measurements will be used to obtain an accurate model to predict mask contribution to wafer overlay and correct for it.

Chou, William; Chang, Hsien-Min; Chen, Chao Yin; Wagner, M.; Roeth, K.-D.; Czerkas, S.; Ferber, M.; Daneshpanah, M.; Laske, F.; Chiang, R.; Klein, S.

2014-04-01

213

Fibre optic sensing using Langmuir-Blodgett thin film overlays  

NASA Astrophysics Data System (ADS)

The development of optical fiber sensors and devices based upon Langmuir-Blodgett thin film overlays deposited onto side polished optical fibers and onto optical fibers containing long period gratings is described.

James, Stephen W.; Ishaq, Imran; Ashwell, Geoffrey J.; Tatam, Ralph P.

2004-06-01

214

Overlay Text Retrieval From Video Scene  

NASA Astrophysics Data System (ADS)

The rapid growth of video data leads to an urgent demand for efficient and true contentbased browsing and retrieving systems. In response to such needs, various video content analysis schemes using one or a combination of image, audio, and text information in videos have been proposed to parse, index, or abstract massive amount of data text in video is a very compact and accurate clue for video indexing and summarization. Most video text detection and extraction methods hold assumptions on text color, background contrast, and font style. Moreover, few methods can handle multilingual text well since different languages may have quite different appearances. In this paper, an efficient overlay text detection and extraction method is implemented which deals with complex backgrounds. Based on our observation that there exist transient colors between inserted text and its adjacent background. It is robust with respect to font size, style text, color, orientation and noise and can be used in a large variety of application fields such as mobile robot navigation vehicle license detection and recognition, object identification , document retrieving, etc.

Manohar, K.; Irfan, S.; Sravani, K.

2013-03-01

215

The Interplanetary Overlay Networking Protocol Accelerator  

NASA Technical Reports Server (NTRS)

A document describes the Interplanetary Overlay Networking Protocol Accelerator (IONAC) an electronic apparatus, now under development, for relaying data at high rates in spacecraft and interplanetary radio-communication systems utilizing a delay-tolerant networking protocol. The protocol includes provisions for transmission and reception of data in bundles (essentially, messages), transfer of custody of a bundle to a recipient relay station at each step of a relay, and return receipts. Because of limitations on energy resources available for such relays, data rates attainable in a conventional software implementation of the protocol are lower than those needed, at any given reasonable energy-consumption rate. Therefore, a main goal in developing the IONAC is to reduce the energy consumption by an order of magnitude and the data-throughput capability by two orders of magnitude. The IONAC prototype is a field-programmable gate array that serves as a reconfigurable hybrid (hardware/ firmware) system for implementation of the protocol. The prototype can decode 108,000 bundles per second and encode 100,000 bundles per second. It includes a bundle-cache static randomaccess memory that enables maintenance of a throughput of 2.7Gb/s, and an Ethernet convergence layer that supports a duplex throughput of 1Gb/s.

Pang, Jackson; Torgerson, Jordan L.; Clare, Loren P.

2008-01-01

216

Graph Based Analysis of Mesh Overlay Streaming Systems  

Microsoft Academic Search

This paper studies fundamental properties of stream-based content distribution services. We assume the presence of an overlay network (such as those built by P2P systems) with limited degree of connectivity, and we develop a mathematical model that captures the essential features of overlay-based streaming protocols and systems. The methodology is based on stochastic graph theory, and models the streaming system

Damiano Carra; Renato Lo Cigno; Ernst W. Biersack

2007-01-01

217

Mixing materials within zone boundaries using shape overlays  

SciTech Connect

Shape overlays provide a means of statically imposing a physical region containing specified material properties onto a zoned mesh. In the most general case, material interface boundaries are unrelated to mesh zone boundaries, causing zones to contain a mixture of materials, and the mesh itself is not uniform in physical space. We develop and apply an algorithm for shape overlays on nonorthogonal, nonuniform meshes in two dimensions. Examples of shape generation in a multiblock uid dynamics code are shown.

Grandy, J.

1997-04-22

218

Landsat Image Mosaic of Antarctica (LIMA)  

USGS Publications Warehouse

For most of us, Antarctica was at best a distant acquaintance. Now, with the Landsat Image Mosaic of Antarctica (LIMA), we are on intimate terms. In stunning, up-close and personal detail, LIMA brings Antarctica to life. Explore this virtually cloudless, seamless, most geometrically accurate, and highest resolution satellite mosaic of Antarctica. A team of scientists from the U.S. Geological Survey, the British Antarctic Survey, and the National Aeronautics and Space Administration, with funding from the National Science Foundation, created LIMA in support of the International Polar Year (IPY; 2007?08). As the first major scientific outcome of the IPY, LIMA truly fulfills the IPY goals. LIMA is an international effort, supports current scientific polar research, encourages new projects, and helps the general public visualize Antarctica and changes happening in this southernmost environment. Researchers and the general public can download LIMA and all component Landsat scenes at no charge.

Geological Survey (U.S.)

2007-01-01

219

Landsat: A Global Land-Imaging Project  

USGS Publications Warehouse

Across nearly four decades since 1972, Landsat satellites continuously have acquired space-based images of the Earth's land surface, coastal shallows, and coral reefs. The Landsat Program, a joint effort of the U.S. Geological Survey (USGS) and the National Aeronautics and Space Administration (NASA), was established to routinely gather land imagery from space; consequently, NASA develops remote-sensing instruments and spacecraft, then launches and validates the satellites. The USGS then assumes ownership and operation of the satellites, in addition to managing all ground-data reception, archiving, product generation, and distribution. The result of this program is a visible, long-term record of natural and human-induced changes on the global landscape.

Headley, Rachel

2010-01-01

220

Landsat: a global land imaging program  

USGS Publications Warehouse

Landsat satellites have continuously acquired space-based images of the Earth's land surface, coastal shallows, and coral reefs across four decades. The Landsat Program, a joint effort of the U.S. Geological Survey (USGS) and the National Aeronautics and Space Administration (NASA), was established to routinely gather land imagery from space. In practice, NASA develops remote-sensing instruments and spacecraft, launches satellites, and validates their performance. The USGS then assumes ownership and operation of the satellites, in addition to managing all ground-data reception, archiving, product generation, and distribution. The result of this program is a visible, long-term record of natural and human-induced changes on the global landscape.

Byrnes, Raymond A.

2012-01-01

221

Earth as Art: A Landsat Perspective  

NSDL National Science Digital Library

For close to thirty years, a series of Landsat satellites have imaged the Earth's surface, returning images for use in a number of business, education, government, and science applications. Of course, many of these images have a great deal of aesthetic value, as those who look at them find themselves marveling at vast deltas, fjords, and land use patterns around the globe. This fine exhibit from the Library of Congress includes images transmitted from Landsat 7. These images are are also part of an exhibit in the Library's Geography & Map Reading Room that will be on display until December 31, 2003. Visitors to the online exhibit can look at high-resolution images of remote Akpatok Island in northern Quebec, Dasht-e Kevir (which translates as Great Salt Desert) in Iran, the West Fjords in northwestern Iceland, and about thirty-five other images in total.

222

SAR/LANDSAT image registration study  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. Temporal registration of synthetic aperture radar data with LANDSAT-MSS data is both feasible (from a technical standpoint) and useful (from an information-content viewpoint). The greatest difficulty in registering aircraft SAR data to corrected LANDSAT-MSS data is control-point location. The differences in SAR and MSS data impact the selection of features that will serve as a good control points. The SAR and MSS data are unsuitable for automatic computer correlation of digital control-point data. The gray-level data can not be compared by the computer because of the different response characteristics of the MSS and SAR images.

Murphrey, S. W. (principal investigator)

1978-01-01

223

Overlay improvements using a real time machine learning algorithm  

NASA Astrophysics Data System (ADS)

While semiconductor manufacturing is moving towards the 14nm node using immersion lithography, the overlay requirements are tightened to below 5nm. Next to improvements in the immersion scanner platform, enhancements in the overlay optimization and process control are needed to enable these low overlay numbers. Whereas conventional overlay control methods address wafer and lot variation autonomously with wafer pre exposure alignment metrology and post exposure overlay metrology, we see a need to reduce these variations by correlating more of the TWINSCAN system's sensor data directly to the post exposure YieldStar metrology in time. In this paper we will present the results of a study on applying a real time control algorithm based on machine learning technology. Machine learning methods use context and TWINSCAN system sensor data paired with post exposure YieldStar metrology to recognize generic behavior and train the control system to anticipate on this generic behavior. Specific for this study, the data concerns immersion scanner context, sensor data and on-wafer measured overlay data. By making the link between the scanner data and the wafer data we are able to establish a real time relationship. The result is an inline controller that accounts for small changes in scanner hardware performance in time while picking up subtle lot to lot and wafer to wafer deviations introduced by wafer processing.

Schmitt-Weaver, Emil; Kubis, Michael; Henke, Wolfgang; Slotboom, Daan; Hoogenboom, Tom; Mulkens, Jan; Coogans, Martyn; ten Berge, Peter; Verkleij, Dick; van de Mast, Frank

2014-04-01

224

Residual stresses in weld overlay tubes: A finite element study  

SciTech Connect

Residual stresses and strains in a tube with circumferential weld overlay were analyzed by the finite element (FE) method. The objective of this work was to develop and verify a FE model, to determine the magnitude and distribution of residual stresses in the weld overlay tube, and to evaluate the significance of two contributing factors to residual stress: (1) difference in material properties between tube and weld material, and (2) thermal gradients in the weld. An axisymmetric FE model was developed to simulate the circumferential two-layer welding process of alloy 625 overlay on SA210 tube. The first layer was modeled as a gas metal arc welding process with filler metal, whereas the autogenous gas tungsten arc welding process was modeled for the second layer. Neutron diffraction technique was used to experimentally determine residual elastic strains in the weld overlay tube. Comparison with the FE results shows overall good agreement. Both the experimental and FE results show high compressive stresses at the inside tube surface and high tensile stresses in the weld overlay. This suggests that weld overlay may be used to relieve tensile or produce compressive stresses at the inside tube surface, which is significant for applications where crack initiation is found at the root pass of the joining weld.

Taljat, B.; Zacharia, T.; Wang, X.L.; Keiser, J.R. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.; Feng, Z. [Edison Welding Inst., Columbus, OH (United States); Jirinec, M.J. [Welding Services, Inc., Norcross, GA (United States)

1997-01-03

225

Factors affecting snow assessment from LANDSAT data  

NASA Technical Reports Server (NTRS)

Problems associated with using LANDSAT as a snow monitoring satellite are studied. Data cover problems of slop hinderance in thematic mapping of snow and detection of snow in forested areas. It was concluded that if detector saturation threshold is raised and the upper spectral limit of the MSS is extended, snow extent mapping will be improved along with the likelihood of monitoring some aspects of the physical condition of snow pack.

Mcginnis, D. F., Jr.; Mcmillan, M. C.; Wiesnet, D. R.

1975-01-01

226

Landsat detection of oil from natural seeps.  

USGS Publications Warehouse

Oil on the ocean surface from the natural seeps in the Santa Barbara Channel, California, could not be detected on frames of any of the four bands of standard Landsat positive or negative film transparencies, nor could the slicks be detected using digital scaling, density slicing, or ratioing techniques. Digital contrast-stretch enhancement, however, showed the distribution of oil on the surface. - from Authors

Deutsch, M.; Estes, J. E.

1980-01-01

227

Midseason mapping of sunflowers using Landsat digital data.  

USGS Publications Warehouse

The mapping results suggest that for the midsummer Landsat data used, there was not a sufficiently reliable relationship between Landsat-derived spectral clusters and sunflowers to allow 'automated' production of useful sunflower location maps. The occurrence of sunflower pixels in all cluster classes was a consequence of the diversity in sunflower appearance at the point in the growing season when the Landsat image used for digital processing was acquired. -Authors

Anderson, W. H.; Ohlen, D. O.; Fairaizl, S. D.

1984-01-01

228

State involvement in and use of LANDSAT technology  

NASA Technical Reports Server (NTRS)

The background of state involvement in LANDSAT systems planning and the status of state LANDSAT use are reviewed. Major recommendations on data continuity; frequency and pattern of observation; state representation in program management; pointable sensors for a fully operational system; data processing systems; data pricing; data copyright; data archival; and technology transfer are highlighted. Plans of the government regarding the LANDSAT system are reflected in the FY-1982 budget process are examined.

Tessar, P. A.

1981-01-01

229

Use of LANDSAT data to assess waterfowl habitat quality  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. The capability of mapping ponds over a very large area was demonstrated, with multidate, multiframe LANDSAT imagery. A small double sample of aircraft data made it possible to adjust a LANDSAT large area census. Terrain classification was improved by using multitemporal LANDSAT data. Waterfowl production was estimated, using remotely determined pond data, in conjunction with FWS estimates of breeding population. Relative waterfowl habitat quality was characterized on a section by section basis.

Colwell, J. E.; Gilmer, D. S. (principal investigators); Work, E. A., Jr.; Rebel, D. L.; Roller, N. E. G.

1978-01-01

230

Landsat-1 and Landsat-2 evaluation report, 23 January 1975 to 23 April 1975  

NASA Technical Reports Server (NTRS)

A description of the work accomplished with the Landsat-1 and Landsat-2 satellites during the period 23 Jan. - 23 Apr. 1975 was presented. The following information was given for each satellite: operational summary, orbital parameters, power subsystem, attitude control subsystem, command/clock subsystem, telemetry subsystem, orbit adjust subsystem, magnetic moment compensating assembly, unified S-band/premodulation processor, electrical interface subsystem, thermal subsystem, narrowband tape recorders, wideband telemetry subsystem, attitude measurement sensor, wideband video tape recorders, return beam vidicon, multispectral scanner subsystem, and data collection subsystem.

1975-01-01

231

Interplanetary Overlay Network Bundle Protocol Implementation  

NASA Technical Reports Server (NTRS)

The Interplanetary Overlay Network (ION) system's BP package, an implementation of the Delay-Tolerant Networking (DTN) Bundle Protocol (BP) and supporting services, has been specifically designed to be suitable for use on deep-space robotic vehicles. Although the ION BP implementation is unique in its use of zero-copy objects for high performance, and in its use of resource-sensitive rate control, it is fully interoperable with other implementations of the BP specification (Internet RFC 5050). The ION BP implementation is built using the same software infrastructure that underlies the implementation of the CCSDS (Consultative Committee for Space Data Systems) File Delivery Protocol (CFDP) built into the flight software of Deep Impact. It is designed to minimize resource consumption, while maximizing operational robustness. For example, no dynamic allocation of system memory is required. Like all the other ION packages, ION's BP implementation is designed to port readily between Linux and Solaris (for easy development and for ground system operations) and VxWorks (for flight systems operations). The exact same source code is exercised in both environments. Initially included in the ION BP implementations are the following: libraries of functions used in constructing bundle forwarders and convergence-layer (CL) input and output adapters; a simple prototype bundle forwarder and associated CL adapters designed to run over an IPbased local area network; administrative tools for managing a simple DTN infrastructure built from these components; a background daemon process that silently destroys bundles whose time-to-live intervals have expired; a library of functions exposed to applications, enabling them to issue and receive data encapsulated in DTN bundles; and some simple applications that can be used for system checkout and benchmarking.

Burleigh, Scott C.

2011-01-01

232

SRTM Perspective with Landsat Virgin Islands, Carribean  

NASA Technical Reports Server (NTRS)

St. Thomas, St. John, Tortola, and Virgin Gorda are the four main islands (front to back) of this east-looking view of the U.S. Virgin Islands and British Virgin Islands, along the northeast perimeter of the Caribbean Sea. For this view, a nearly cloud-free Landsat image was draped over elevation data from the Shuttle Radar Topography Mission (SRTM), and shading derived from the SRTM data was added to enhance the topographic expression. Elevation is shown with 1.5x scaled vertical exaggeration. Coral reefs fringe the islands in many locations and appear as very light shades of blue. Tropical vegetation appears green, and developed areas appear in shades of brown and white.

As in much of the world, topography is the primary factor in the pattern of land use development in the Virgin Islands. Topography across most of the islands is quite rugged, and although the steep slopes create a scenic setting, they crowd most development into the small areas of low relief terrain, generally along the shoreline. The topographic pattern also affects water supply, wastewater disposal, landfill locations, road construction, and most other features of the development infrastructure. Topography also defines the natural drainage pattern, which is the major consideration in anticipating tropical storm water runoff dangers, as well as the dangers of heightened sediment impacts upon the adjacent coral reefs.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and substantially helps in analyzing the large and growing Landsat image archive.

Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on February 11, 2000. The mission used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar that flew twice on the Space Shuttle Endeavour in 1994. The Shuttle Radar Topography Mission was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C.

Size: 94.7 kilometers (58.7 miles) view distance, 29.2 kilometers (18.1 miles) view width Location: 18.25 degrees North latitude, 64.75 degrees West longitude Orientation: Looking EasT Image Data: Landsat Bands 1,2+4, 3 as blue, green, red, respectively Original Data Resolution: SRTM and Landsat 30 meters (99 feet) Date Acquired: February 2000 (SRTM), January 21, 1985 (Landsat)

2003-01-01

233

Anaglyph with Landsat Virgin Islands, Caribbean  

NASA Technical Reports Server (NTRS)

St. Thomas, St. John, Tortola, and Virgin Gorda are the four main islands (lower left to upper right) of this map-view anaglyph of the U.S. Virgin Islands and British Virgin Islands, along the northeast perimeter of the Caribbean Sea. For this view, a nearly cloud-free Landsat image was draped over elevation data from the Shuttle Radar Topography Mission (SRTM), and shading derived from the SRTM data was added to enhance the topographic expression. Coral reefs fringe the islands in many locations and appear as bright patterns in near-shore waters. Tropical vegetation appears fairly dark with smooth tones, as compared to the brighter speckled patterns of towns and other developments.

As in much of the world, topography is the primary factor in the pattern of land use development in the Virgin Islands. Topography across most of the islands is quite rugged, and although the steep slopes create a scenic setting, they crowd most development into the small areas of low relief terrain, generally along the shoreline. The topographic pattern also affects water supply, wastewater disposal, landfill locations, road construction, and most other features of the development infrastructure. Topography also defines the natural drainage pattern, which is the major consideration in anticipating tropical storm water runoff dangers, as well as the dangers of heightened sediment impacts upon the adjacent coral reefs.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and substantially helps in analyzing the large and growing Landsat image archive.

Elevation data used in this image were acquired by the Shuttle Radar Topography Mission aboard the Space Shuttle Endeavour, launched on February 11, 2000. The mission used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar that flew twice on the Space Shuttle Endeavour in 1994. The Shuttle Radar Topography Mission was designed to collect three-dimensional measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter-long (200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency of the U.S. Department of Defense, and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C.

Size: 79.9 by 48.6 kilometers (49.9 by 30.1 miles) Location: 18.25 degrees North latitude, 64.75 degrees West longitude Orientation: North-Northeast toward the top Image Data: Landsat Band 1 with SRTM shading Original Data Resolution: SRTM and Landsat 30 meters (99 feet) Date Acquired: February 2000 (SRTM), January 21, 1985 (Landsat)

2003-01-01

234

LANDSAT: Non-US standard catalog. [LANDSAT imagery for August 1977  

NASA Technical Reports Server (NTRS)

The non-U. S. Standard Catalog lists non-U. S. imagery acquired by LANDSAT 1 and 2 which has been processed and input to the data files during the referenced month. Data, such as date acquired, cloud cover and image quality are given for each scene. The microfilm roll and frame on which the scene may be found is also given.

1977-01-01

235

LANDSAT-1 and LANDSAT-2 flight evaluation report, 23 January - 23 April 1977  

NASA Technical Reports Server (NTRS)

The LANDSAT operations from launch through orbital instrument observations are reviewed. Orbital parameters, power subsystem, attitude control subsystem, and command/clock subsystem are discussed. Other subsystems are also considered, such as telemetry, orbit adjust, electrical interface, thermal, wideband telemetry, multispectral scanner, and data collection.

1977-01-01

236

Instructional geographic information science Map overlay and spatial abilities  

NASA Astrophysics Data System (ADS)

The fundamental goal of this study is to determine if the complex spatial concept of map overlay can be effectively learned by young adolescents through the utilization of an instructional technique based within the foundations of Instructional Geographic Information Science (InGIScience). Percent correct and reaction times were the measures used to analyze the ability of young adolescents to learn the intersect, erase, and union functions of map overlay. The ability to solve for missing inputs, output, or function was also analyzed. Young adolescents of the test group scored higher percent correct and recorded faster reaction times than those of the control group or adults of the expert group by the end of the experiment. The intersect function of map overlay was more difficult in terms of percent correct and reaction time than the erase or union functions. Solving for the first or second input consistently resulted in lower percent correct and higher reaction times throughout the experiment. No overall performance differences were shown to exist between males and females. Results of a subjective "real-world" test also indicated learning by young adolescents. This study has shown that the practice of repetitive instruction and testing has proven effective for enhancing spatial abilities with regard to the map overlay concept. This study found that with practice, young adolescents can learn the map overlay concept and perform at levels equal to or greater than adults. This study has helped to answer the question of whether this development of spatial abilities is possible.

Tricot, Thomas Alexander, II

237

Investigation on reticle heating effect induced overlay error  

NASA Astrophysics Data System (ADS)

As design rule of semiconductor decreases continuously, overlay error control gets more and more important and challenging. It is also true that On Product Overlay (OPO) of leading edge memory device shows unprecedented level of accuracy, owing to the development of precision optics, mechanic stage and alignment system with active compensation method. However, the heating of reticle and lens acts as a dominant detriment against further improvement of overlay. Reticle heating is more critical than lens heating in current advanced scanners because lens heating can be mostly compensated by feed-forward control algorithm. In recent years, the tools and technical ideas for reticle heating control are proposed and thought to reduce the reticle heating effect. Nevertheless, it is not still simple to predict the accurate heating amount and overlay. And it is required to investigate the parameters affecting reticle heating quantitatively. In this paper, the reticle pattern density and exposure dose are considered as the main contributors, and the effects are investigated through experiments. Mask set of various transmittance are prepared by changing pattern density. After exposure with various doses, overlay are measured and analyzed by comparing with reference marks exposed in heating free condition. As a result, it is discovered that even in the case of low dose and high transmittance, reticle heating is hardly avoidable. It is also shown that there is a simple relationship among reticle heating, transmittance and exposure dose. Based on this relationship, the reticle heating is thought to be predicted if the transmittance and dose are fixed.

Lim, Mijung; Kim, Geunhak; Kim, SeoMin; Lee, Byounghoon; Kim, Seokkyun; Lim, Chang-moon; Kim, Myoungsoo; Park, Sungki

2014-04-01

238

Landsat: The Backbone for Mapping and Monitoring Global Ecological Trends  

NASA Astrophysics Data System (ADS)

Long-term ecological monitoring requires consistent observation of key variables, long-term measurement continuity, and open and affordable access to measurements. The Landsat series of Earth observation missions uniquely meet those criteria, and Landsat's 30m-observation scale permits the detection and differentiation of natural versus human-caused land change. Landsat is the longest and most comprehensive record of the state of the global land surface in existence. No other high-resolution satellite program is either capable or committed to the systematic monitoring of global scale human and natural land change. Beginning with Landsat 1 in 1972, six Landsat missions have continuously recorded images of the Earth. As we near the fortieth anniversary of Landsat, we now have an archive of millions of repetitive images of the Earth with multispectral properties suited to assessing both biotic and abiotic conditions and at a scale appropriate for resource management. The U.S. Geological Survey's (USGS) Earth Resources Observations Systems (EROS) Landsat archive contains nearly three million scenes and all are available to users at no cost. Furthermore, the entire Landsat record, Landsats 1-7, is now calibrated to a common radiometric standard and the majority of the data are orthorectified - enabling immediate assessment of long-term ecological conditions and land change. Landsats 5 and 7 continue to collect imagery and together they provide the potential to cover a significant portion of the Earth's land surfaces every eight days. Both of these missions now use a long-term acquisition plan designed to improve the collection of seasonal global coverage. Furthermore, recent agreements with international Landsat receiving stations are bringing previously inaccessible contemporary Landsat 5 data into the EROS archive. The amount of global coverage being acquired annually is the highest level in the history of the Landsat program. The EROS global historical archive is rapidly expanding because of the addition of 1972-present Landsat holdings from ground stations worldwide. More than three million Landsat scenes not currently found in the EROS archive exist in archives around the world and many of these data are at risk due to aging storage media and inadequate preservation practices. The repatriation of these data into the EROS archive will potentially double the number of no-cost Landsat scenes available to users. The uncertainty of future Landsat missions has challenged operational monitoring of ecological systems. However, that may be changing. The Landsat Data Continuity Mission (LDCM) being developed by NASA and the USGS is slated for a December 2012 launch. LDCM (which will be renamed Landsat 8 following launch) will use new imaging technology to provide improved multispectral measurements, and offers additional spectral bands and increased daily imaging capacity. While missions beyond LDCM are uncertain, the President's Fiscal Year 2012 budget requests funds for the planning and development of Landsats 9 and 10, and includes language that will make Landsat an operational program - ending the decades of uncertainty.

Loveland, T. R.

2011-12-01

239

Modeling Pine Plantation NEP Using Landsat  

NASA Astrophysics Data System (ADS)

The CASA (Carnegie Ames Stanford Approach) ecosystem process model predicts terrestrial ecosystem fluxes using satellite-based inputs at a maximum geographic resolution of 30 meters to infer variability in forest carbon fluxes. We are using CASA to model pine plantation net ecosystem production (NEP) under a range of standard silvicultural prescriptions, primarily thinning by fertilization interactions. Landsat scenes from WRS path/row 14/35, 21/37, and 16/34 are being used. Within each frame, all available cloud-free scenes within a two- to three-year period have been obtained from the USGS EROS Data Center processed to L1T, and subsequently converted to top-of-atmosphere reflectance using standard methods and the latest calibration parameter files. Atmospheric amelioration started with dark object subtraction (band minimum) and only proceeded to more complex techniques as necessary. Subsequent to preprocessing, the reduced simple ratio (RSR; using global min/max) was calculated for all images for each WRS path/row. Pure pine pixels in each frame were identified using unsupervised classification of the most recent leaf-off scene. We developed four age classes using two decades of Landsat data over each WRS path/row. CASA runs, which require soil parameters, and gridded climate/solar radiation in addition to satellite-derived vegetation indices, are now complete. Soil respiration and productivity estimates are being evaluated using a regionwide network of validation sites spanning the range of loblolly pine (Texas to Virginia). Preliminary results indicate that Landsat-based process modeling (1) is necessary for the scale at which land is actually managed and (2) produces estimates with an accuracy and precision affording improved understanding and management of forest ecosystems.

Wynne, R. H.; Potter, C. S.; Blinn, C. E.

2008-12-01

240

LANDSAT-D Worldwide Reference System (WRS) users guide  

NASA Technical Reports Server (NTRS)

A functional description of the LANDSAT-D Worldwide Reference System (WRS) and an overview of the main orbital parameters and instrument coverages are presented. The primary information required to understand the LANDSAT-D orbital characteristics, to effectively use the Worldwide Reference System (WRS) indexing scheme, and to request specific geographic coverage on the desired observation dates is provided.

1981-01-01

241

LANDSAT 2 cumulative non-US standard catalog  

NASA Technical Reports Server (NTRS)

The Non-U.S. Standard Catalog lists imagery acquired by LANDSAT 1 and LANDSAT 2 which has been processed and input to the data files during the referred month. Data, such as data acquired, cloud cover and image quality are given for each scene. The microfilm roll and frame on which the scene may be found is also given.

1977-01-01

242

LANDSAT US standard catalog, 1-31 March 1976  

NASA Technical Reports Server (NTRS)

The U.S. Standard Catalog lists U.S. imagery acquired by LANDSAT 1 and LANDSAT 2 which has been processed and input to the data files during the referenced month. Data, such as date acquired, cloud cover and image quality are given for each scene. The microfilm roll and frame on which the scene may be found is also given.

1976-01-01

243

Landsat maps of Iraq: tools for non-invasive exploration  

Microsoft Academic Search

Optical analysis of Landsat imagery is a valuable preliminary step for exploration in areas where a detailed geologic base is lacking, logistics are difficult, or the political situation is insecure. Two maps of Iraq produced by such analysis elucidate structural and lithologic relations across a broad oil-producing region. The Landsat map of Iraq is divided into units based on drainage

S. L. Gawarecki; S. K. Perry

1984-01-01

244

Historical Landsat data comparisons: illustrations of land surface change  

USGS Publications Warehouse

The U.S. Geological Survey's (USGS) EROS Data Center (EDC) has archived two decades of Landsat data, providing a rich collection of information about the dynamics of the Earth's land surface. Major changes to the surface features of the planet can be detected, measured, and studied using Landsat data. The effects of desertification, deforestation, pollution, cataclysmic volcanic activity, and other natural and anthropogenic events can be examined by resource scientists using data acquired from the Landsat series of Earth-observing satellites. The availability of a nearly uninterrupted flow of information from the Landsats, in a consistent data format, gives researchers an important tool for studying surface changes over time. This booklet provides an overview of the Landsat program and shows the application of the data to monitor changes occurring on the surface of the Earth. To show changes that have taken place within the last 20 years or less, image pairs were constructed from the Landsat multispectral scanner (MSS) and thematic mapper (TM) sensors. Landsat MSS data provide a historical global record of the land surface from the early 1970's to present. Landsat TM data provide land surface information from the early 1980's to present.

Cross, Matthew D.

245

Historical Landsat data comparisons: illustrations of the Earth's changing surface  

USGS Publications Warehouse

The U.S. Geological Survey's (USGS) EROS Data Center (EDC) has managed the Landsat data archive for more than two decades. This archive provides a rich collection of information about the Earth's land surface. Major changes to the surface of the planet can be detected, measured, and analyzed using Landsat data. The effects of desertification, deforestation, pollution, cataclysmic volcanic activity, and other natural and anthropogenic events can be examined using data acquired from the Landsat series of Earth-observing satellites. The information obtainable from the historical and current Landsat data play a key role in studying surface changes through time. This document provides an overview of the Landsat program and illustrates the application of the data to monitor changes occurring on the surface of the Earth. To reveal changes that have taken place within the past 20 years, pairs and triplicates of images were constructed from the Landsat multispectral scanner (MSS) and thematic mapper (TM) sensors. Landsat MSS data provide a historical record of the Earth's land surface from the early 1970's to the early 1990's. Landsat TM data provide land surface information from the early 1980's to the present.

U.S. Geological Survey

1995-01-01

246

Multidate Landsat lake quality monitoring program  

NASA Technical Reports Server (NTRS)

A unified package of files and programs has been developed to automate the multidate Landsat-derived analyses of water quality for about 3000 inland lakes throughout Wisconsin. A master lakes file which stores geographic information on the lakes, a file giving the latitudes and longitudes of control points for scene navigation, and a program to estimate control point locations and produce microfiche character maps for scene navigation are among the files and programs of the system. The use of ground coordinate systems to isolate irregular shaped areas which can be accessed at will appears to provide an economical means of restricting the size of the data set.

Fisher, L. T.; Scarpace, F. L.; Thomsen, R. G.

1979-01-01

247

LANDSAT-4 band 6 data evaluation  

NASA Technical Reports Server (NTRS)

The radiometric integrity of the LANDSAT-D thematic mapper (TM) thermal infrared channel (band 6) data was evaluated to develop improved radiometric preprocessing calibration techniques for removal of atmospheric effects. Primary data analysis was spent in evaluating the line to line and detector to detector variation in the thermal infrared data. The data studied was in the core area of Lake Ontario where very stable temperatures were expected. The detectors and the scan direction were taken as separate parameters and an analysis of variance was conducted. The data indicate that significant variability exists both between detectors and between scan directions.

1983-01-01

248

Lake water quality mapping from Landsat  

NASA Technical Reports Server (NTRS)

In the project described remote sensing was used to check the quality of lake waters. The lakes of three Landsat scenes were mapped with the Bendix MDAS multispectral analysis system. From the MDAS color coded maps, the lake with the worst algae problem was easily located. The lake was closely checked, and the presence of 100 cows in the springs which fed the lake could be identified as the pollution source. The laboratory and field work involved in the lake classification project is described.

Scherz, J. P.

1977-01-01

249

Landsat - What is operational in water resources  

NASA Technical Reports Server (NTRS)

Applications of Landsat data in hydrology and water quality measurement were examined to determine which applications are operational. In hydrology, the principal applications have been surface water inventory, and land cover analysis for (1) runoff modeling and (2) abatement planning for non-point pollution and erosion. In water quality measurement, the principal applications have been: (1) trophic state assessment, and (2) measurement of turbidity and suspended sediment. The following applications were found to be operational: mapping of surface water, snow cover, and land cover (USGS Level 1) for watershed applications; measurement of turbidity, Secchi disk depth, suspended sediment concentration, and water depth.

Middleton, E. M.; Munday, J. C., Jr.

1981-01-01

250

California coastal processes study, LANDSAT 2  

NASA Technical Reports Server (NTRS)

The authors have identified the following significant results. By using suspended sediments as tracers, objectives were met by qualitative definition of the nearshore circulation along the entire coast of California with special study sites at Humboldt Bay, the mouth of the Russian River, San Francisco Bay, Monterey Bay, and the Santa Barbara Channel. Although LANDSAT primarily imaged fines and silts in the surface waters, the distribution of sediments allowed an examination of upwelling, convergences and coastal erosion and deposition. In Monterey Bay and Humboldt Bay, these coastal phenomena were used to trace seasonal trends in surface currents.

Pirie, D. M.; Steller, D. D. (principal investigators)

1977-01-01

251

Landsat 7 Solar Array Testing Experiences  

NASA Technical Reports Server (NTRS)

This paper covers the extensive Landsat 7 solar array flight qualification testing effort. Details of the mechanical design of the solar array and its retention/release system are presented. A testing chronology is provided beginning with the onset of problems encountered at the subsystem level and carrying through the third and final powered-spacecraft ground deployment test. Design fixes and other changes are explained in the same order as they became necessary to flight-qualify the array. Some interesting lessons learned are included along with key references.

Helfrich, Daniel

2000-01-01

252

Operational alternatives for LANDSAT in California  

NASA Technical Reports Server (NTRS)

Data integration is defined and examined as the means of promoting data sharing among the various governmental and private geobased information systems in California. Elements of vertical integration considered included technical factors (such as resolution and classification) and institutional factors (such as organizational control, and legal and political barriers). Attempts are made to fit the theoretical elements of vertical integration into a meaningful structure for looking at the problem from a statewide focus. Both manual (mapped) and machine readable data systems are included. Special attention is given to LANDSAT imagery because of its strong potential for integrated use and its primary in the California Integrated Remote Sensing System program.

Wilson, P.; Gialdini, M. J.

1981-01-01

253

Improved LANDSAT to give better view of earth resources  

NASA Technical Reports Server (NTRS)

The launch data of LANDSAT 3 is announced. The improved capability of the spacecrafts' remote sensors (the return beam vidicon and the multispectral scanner) and application of LANDSAT data to the study of energy supplies, food production, and global large-scale environmental monitoring are discussed along with the piggyback amateur radio communication satellite-OSCAR-D, the plasma Interaction Experiment, and the data collection system onboard LANDSAT 3. An assessment of the utility of LANDSAT multispectral data is given based on the research results to data from studies of LANDSAT 1 and 2 data. Areas studied include agriculture, rangelands, forestry, water resources, environmental and marine resources, environmental and marine resources, cartography, land use, demography, and geological surveys and mineral/petroleum exploration.

1978-01-01

254

Revised landsat-5 thematic mapper radiometric calibration  

USGS Publications Warehouse

Effective April 2, 2007, the radiometric calibration of Landsat-5 (L5) Thematic Mapper (TM) data that are processed and distributed by the U.S. Geological Survey (USGS) Center for Earth Resources Observation and Science (EROS) will be updated. The lifetime gain model that was implemented on May 5, 2003, for the reflective bands (1-5, 7) will be replaced by a new lifetime radiometric-calibration curve that is derived from the instrument's response to pseudoinvariant desert sites and from cross calibration with the Landsat-7 (L7) Enhanced TM Plus (ETM+). Although this calibration update applies to all archived and future L5 TM data, the principal improvements in the calibration are for the data acquired during the first eight years of the mission (1984-1991), where the changes in the instrument-gain values are as much as 15%. The radiometric scaling coefficients for bands 1 and 2 for approximately the first eight years of the mission have also been changed. Users will need to apply these new coefficients to convert the calibrated data product digital numbers to radiance. The scaling coefficients for the other bands have not changed. ?? 2007 IEEE.

Chander, G.; Markham, B. L.; Barsi, J. A.

2007-01-01

255

LANDSAT-D investigations in snow hydrology  

NASA Technical Reports Server (NTRS)

Work undertaken during the contract and its results are described. Many of the results from this investigation are available in journal or conference proceedings literature - published, accepted for publication, or submitted for publication. For these the reference and the abstract are given. Those results that have not yet been submitted separately for publication are described in detail. Accomplishments during the contract period are summarized as follows: (1) analysis of the snow reflectance characteristics of the LANDSAT Thematic Mapper, including spectral suitability, dynamic range, and spectral resolution; (2) development of a variety of atmospheric models for use with LANDSAT Thematic Mapper data. These include a simple but fast two-stream approximation for inhomogeneous atmospheres over irregular surfaces, and a doubling model for calculation of the angular distribution of spectral radiance at any level in an plane-parallel atmosphere; (3) incorporation of digital elevation data into the atmospheric models and into the analysis of the satellite data; and (4) textural analysis of the spatial distribution of snow cover.

Dozier, J. (principal investigator); Davis, R. E.; Dubayah, R. O.; Frew, J. E.; Li, S.; Marks, D.; Milliff, R. F.; Rousseau, D. D.; Wan, Z. M.

1985-01-01

256

Geospatial Method for Computing Supplemental Multi-Decadal U.S. Coastal Land-Use and Land-Cover Classification Products, Using Landsat Data and C-CAP Products  

NASA Technical Reports Server (NTRS)

This paper discusses the development and implementation of a geospatial data processing method and multi-decadal Landsat time series for computing general coastal U.S. land-use and land-cover (LULC) classifications and change products consisting of seven classes (water, barren, upland herbaceous, non-woody wetland, woody upland, woody wetland, and urban). Use of this approach extends the observational period of the NOAA-generated Coastal Change and Analysis Program (C-CAP) products by almost two decades, assuming the availability of one cloud free Landsat scene from any season for each targeted year. The Mobile Bay region in Alabama was used as a study area to develop, demonstrate, and validate the method that was applied to derive LULC products for nine dates at approximate five year intervals across a 34-year time span, using single dates of data for each classification in which forests were either leaf-on, leaf-off, or mixed senescent conditions. Classifications were computed and refined using decision rules in conjunction with unsupervised classification of Landsat data and C-CAP value-added products. Each classification's overall accuracy was assessed by comparing stratified random locations to available reference data, including higher spatial resolution satellite and aerial imagery, field survey data, and raw Landsat RGBs. Overall classification accuracies ranged from 83 to 91% with overall Kappa statistics ranging from 0.78 to 0.89. The accuracies are comparable to those from similar, generalized LULC products derived from C-CAP data. The Landsat MSS-based LULC product accuracies are similar to those from Landsat TM or ETM+ data. Accurate classifications were computed for all nine dates, yielding effective results regardless of season. This classification method yielded products that were used to compute LULC change products via additive GIS overlay techniques.

Spruce, J. P.; Smoot, James; Ellis, Jean; Hilbert, Kent; Swann, Roberta

2012-01-01

257

Robotic weld overlay coatings for erosion control. Quarterly progress report, October 1993--December 1993.  

National Technical Information Service (NTIS)

Research is being conducted to develop criteria for selecting weld overlay coatings for erosion mitigation in Circulated Fluidized Beds. Twelve weld overlay alloys were deposited on 1018 steel substrates using plasma arc welding. Ten samples from each coa...

B. F. Levin J. N. DuPont A. R. Marder

1994-01-01

258

Dynamic Internet Overlay Deployment and Management Using the X-Bone  

Microsoft Academic Search

The X-Bone dynamically deploys and manages Internet overlays to reduce their configuration effort and increase network component sharing. The X-Bone discovers, configures, and monitors network resources to create overlays over existing IP networks. Overlays are useful for deploying overlapping virtual networks on shared infrastructure and for simplifying topology. The X-Bone extends current overlay management by adding dynamic resource discovery, deployment,

Joseph D. Touch

2000-01-01

259

Performance Evaluation and Comparison of Tree and Ring Application-Layer Multicast Overlay Networks  

Microsoft Academic Search

Application-layer multicast (ALM) protocols differ in, among other aspects, the topology of the underlying overlay network (e.g., tree, mesh or ring). Therefore, comparing the performance of ALM overlay networks is an important step to- wards assessing the inherent advantages and\\/or limitations of each overlay network topology. In particular, ring-based ALM overlay networks have the advantages of (a) providing a con-

Ahmed Sobeih; Jun Wang; William Yurcik

260

Investigation of radiometric properties of the LANDSAT-4 multispectral scanner  

NASA Technical Reports Server (NTRS)

The radiometric data quality of the LANDSAT 4 multispectral scanner (MSS) was examined using several LANDSAT 4 frames. It was found that LANDSAT 4 MSS produces high-quality data of the caliber experienced with previous LANDSATS. For example, the detector equalization procedure worked well, leaving a residual banding effect of about 0.3 digital counts RMS, close to the theoretical minimum value of quantization error. Nevertheless, artifacts of the data were found, two of which were not experienced in previous MSS data. A low-level coherent noise effect was observed in all bands, with a magnitude of about 0.5 digital counts and a frequency of approximately 28 KHz (representing a wavelength of about 3.6 pixels); a substantial increase in processing complexity would be required to reduce this artifact in the data. Also, a substantial scan-length variation (of up to six pixels) was noted in MSS data when the TM sensor was operating; the LANDSAT 4 correction algorithms being applied routinely by the EROS Data Center to produce a p-type data should remove most of this variation. Between-satellite calibrations were examined in paired LANDSAT 3 and LANDSAT 4 MSS data sets, which were closely matched in acquisition time and place. Radiometric comparisons showed that all bands were highly linear in digital counts, and a well-determined linear transformation between the MSS's was established.

Malila, W. A. (principal investigator); Rice, D. P.

1983-01-01

261

A comparative reliability analysis of computer-generated bitemark overlays.  

PubMed

This study compared the reliability of two methods used to produce computer-generated bitemark overlays with Adobe Photoshop (Adobe Systems Inc., San Jose, CA). Scanned images of twelve dental casts were sent to 30 examiners with different experience levels. Examiners were instructed to produce an overlay for each cast image based on the instructions provided for the two techniques. Measurements of the area and the x-y coordinate position of the biting edges of the anterior teeth were obtained using Scion Image software program (Scion Corporation, Frederick, MD) for each overlay. The inter- and intra-reliability assessment of the measurements was performed using an analysis of variance and calculation of reliability coefficients. The assessment of the area measurements showed significant variances seen in the examiner variable for both techniques resulting in low reliability coefficients. Conversely, the results for the positional measurements showed no significant differences in the variances between examiners with exceptionally high reliability coefficients. It was concluded that both techniques were reliable methods to produce bitemark overlays in assessing tooth position. PMID:15818864

McNamee, Anne H; Sweet, David; Pretty, Iain

2005-03-01

262

MACEDON: Methodology for Automatically Creating, Evaluating, and Designing Overlay Networks  

Microsoft Academic Search

Currently, researchers designing and implementing large- scale overlay services employ disparate techniques at each stage in the production cycle: design, implemen- tation, experimentation, and evaluation. As a result, complex and tedious tasks are often duplicated leading to ineectiv e resource use and dicult y in fairly com- paring competing algorithms. In this paper, we present MACEDON, an infrastructure that provides

Adolfo Rodriguez; Charles Edwin Killian; Sooraj Bhat; Dejan Kostic; Amin Vahdat

2004-01-01

263

Modeling of glass?steel overlay and snow load  

Microsoft Academic Search

This paper presents the analysis of the spatial prismatic sloped overlay of irregular shape with a spherical surface upon. This bearing steel structure is under a dead?load of a framed glass packet and under snow. Mathematical model of prism and spheroid geometry is developed. Construction geometry of a rectangularly profiled pipe and snow pressure is modelled in finite elements, using

Valentinas Skaržauskas; Valentin Jankovski; Juozas Atko?i?nas

2006-01-01

264

Characterizing Traffic Demand Aware Overlay Routing Network Topologies  

Microsoft Academic Search

We introduce a traffic demand aware cost model for the creation of overlay routing networks. We investigate the effects on the created network topologies when the traffic demand between nodes is considered. The resulting network topologies often differ dramatically from topologies formed when traffic demand between nodes is not weighed. We found that the global network characteristics were changed as

Benjamin D. McBride; Caterina Scoglio

2007-01-01

265

Styrene-Butadiene Latex Modifiers for Bridge Deck Overlay Concrete.  

National Technical Information Service (NTIS)

Styrene-butadiene (S/B) latex modified concrete overlays are being used to protect new bridge decks from rapid deicer-borne chloride intrusion and also in bridge deck rehabilitation efforts. The purposes of this research were to evaluate several commercia...

B. H. Chollar K. C. Clear

1978-01-01

266

Semantic overlay network for large-scale spatial information indexing  

NASA Astrophysics Data System (ADS)

The increased demand for online services of spatial information poses new challenges to the combined filed of Computer Science and Geographic Information Science. Amongst others, these include fast indexing of spatial data in distributed networks. In this paper we propose a novel semantic overlay network for large-scale multi-dimensional spatial information indexing, called SON_LSII, which has a hybrid structure integrating a semantic quad-tree and Chord ring. The SON_LSII is a small world overlay network that achieves a very competitive trade-off between indexing efficiency and maintenance overhead. To create SON_LSII, we use an effective semantic clustering strategy that considers two aspects, i.e., the semantic of spatial information that peer holds in overlay network and physical network performances. Based on SON_LSII, a mapping method is used to reduce the multi-dimensional features into a single dimension and an efficient indexing algorithm is presented to support complex range queries of the spatial information with a massive number of concurrent users. The results from extensive experiments demonstrate that SON_LSII is superior to existing overlay networks in various respects, including scalability, maintenance, rate of indexing hits, indexing logical hops, and adaptability. Thus, the proposed SON_LSII can be used for large-scale spatial information indexing.

Zou, Zhiqiang; Wang, Yue; Cao, Kai; Qu, Tianshan; Wang, Zhongmin

2013-08-01

267

Crosslayer Survivability in Overlay-IP-WDM Networks  

ERIC Educational Resources Information Center

As the Internet moves towards a three-layer architecture consisting of overlay networks on top of the IP network layer on top of WDM-based physical networks, incorporating the interaction between and among network layers is crucial for efficient and effective implementation of survivability. This dissertation has four major foci as follows:…

Pacharintanakul, Peera

2010-01-01

268

A hybrid overlay network for video-on-demand  

Microsoft Academic Search

On-demand video streaming through overlay networks has received much attention recently. While a tree topology is often advocated in such systems, it suffers from discontinuous playback under the highly dynamic Internet environment with frequent node joins and leaves. On the other hand, gossip protocols using random message dissemination, though robust, fail to meet the real-time demands for streaming applications. In

Ming Zhou; Jiangchuan Liu

2005-01-01

269

Incidental Learning of Geospatial Concepts across Grade Levels: Map Overlay  

ERIC Educational Resources Information Center

In this paper, the authors evaluate map overlay, a concept central to geospatial thinking, to determine how it is naively and technically understood, as well as to identify when it is leaner innately. The evaluation is supported by results from studies at three grade levels to show the progression of incidentally learned geospatial knowledge as…

Battersby, Sarah E.; Golledge, Reginald G.; Marsh, Meredith J.

2006-01-01

270

Multicast Overlay Spanning Tree Protocol for Ad Hoc Networks  

Microsoft Academic Search

In this paper we present an extension to the OLSR unicast routing protocol to support multicast routing in mobile ad hoc networks. The proposed protocol is based on Multicast Overlay Spanning Trees (MOST). The main beneflts of this approach are twofold. Firstly, it im- plies that only nodes interested in taking part in the multicast communi- cation need to participate

Georgios Rodolakis; Amina Meraihi Naimi; Anis Laouiti

2007-01-01

271

Performance of an Unbonded Concrete Overlay on I-74.  

National Technical Information Service (NTIS)

In Illinois, the typical rehabilitation for a concrete pavement is full-depth patching of the distressed concrete, and overlaying the pavement with 3.25 inches of bituminous concrete. In cases where there are poor joints or extensive durability cracking o...

L. B. Heckel

2002-01-01

272

Experimental determination of the residual stresses in a spiral weld overlay tube  

Microsoft Academic Search

Neutron diffraction was used to determine the residual stresses in a spiral weld overlay tube. The specimen was a 2.5 in. OD carbon steel tube covered with a layer of alloy 625 weld overlay. Residual strains in the carbon steel and weld overlay layers were determined using the ferritic (211) and austenitic (311) reflections, respectively. The residual stresses in each

X.-L. Wang; E. A. Payzant; B. Taljat; C. R. Hubbard; J. R. Keiser; M. J. Jirinec

1997-01-01

273

OMNI: An efficient overlay multicast infrastructure for real-time applications  

Microsoft Academic Search

We consider an overlay architecture (called OMNI) where service providers deploy a set of service nodes (called MSNs) in the network to efficiently implement media-streaming applications. These MSNs are organized into an overlay and act as application-layer multicast forwarding entities for a set of clients. We present a decentralized scheme that organizes the MSNs into an appropriate overlay structure that

Suman Banerjee; Christopher Kommareddy; Koushik Kar; Bobby Bhattacharjee; Samir Khuller

2006-01-01

274

Construction of an Efficient Overlay Multicast Infrastructure for Real-time Applications  

Microsoft Academic Search

We consider an overlay architecture where service providers deploy a set of service nodes (called MSNs) in the network to efficiently implement media-streaming applications. These MSNs are organized into an overlay and act as application- layer multicast forwarding entities for a set of clients. We present a decentralized scheme that organizes the MSNs into an appropriate overlay structure that is

Suman Banerjee; Christopher Kommareddy; Koushik Kar; Samrat Bhattacharjee; Samir Khuller

2003-01-01

275

vuv synchrotron light as a technique for studying the interface quality and properties of thin overlayers  

SciTech Connect

The measurements presented here show the value of synchrotron light for determining both the electronic structure of overlayers, and the physical nature of the overlayer-substrate interface. A comparison is given between deposited layers and thermally stabilized layers. Estimates are also made of the bonding energy between the overlayer and substrate.

Ruckman, M.W.; Murgai, V.; Strongin, M.

1984-12-01

276

Geometric accuracy of Landsat-4 and Landsat-5 Thematic Mapper images.  

USGS Publications Warehouse

The geometric accuracy of the Landsat Thematic Mappers was assessed by a linear least-square comparison of the positions of conspicuous ground features in digital images with their geographic locations as determined from 1:24 000-scale maps. For a Landsat-5 image, the single-dimension standard deviations of the standard digital product, and of this image with additional linear corrections, are 11.2 and 10.3 m, respectively (0.4 pixel). An F-test showed that skew and affine distortion corrections are not significant. At this level of accuracy, the granularity of the digital image and the probable inaccuracy of the 1:24 000 maps began to affect the precision of the comparison. The tested image, even with a moderate accuracy loss in the digital-to-graphic conversion, meets National Horizontal Map Accuracy standards for scales of 1:100 000 and smaller. Two Landsat-4 images, obtained with the Multispectral Scanner on and off, and processed by an interim software system, contain significant skew and affine distortions. -Authors

Borgeson, W. T.; Batson, R. M.; Kieffer, H. H.

1985-01-01

277

LANDSAT-D thermal analysis and design support  

NASA Technical Reports Server (NTRS)

Detailed thermal models of the LANDSAT-D Earth Sensor Assembly Module (ESAM), the Dummy Thematic Mapper (DTM), and a small thermal model of the LANDSAT-D spacecraft for a heater analysis were developed. These models were used to develop and verify the thermal design of the ESAM and DTM, to evaluate the aeroheating effects on ESAM during launch and to evaluate the thermal response of the LANDSAT-D assuming the hard-line heaters failed on with the spacecraft in the Space Transportation System (STS) orbiter bay. Results of model applications are summarized.

1982-01-01

278

Enumeration of prairie wetlands with Landsat and aircraft data  

USGS Publications Warehouse

A method is described for making an estimate of wetland numbers in the glaciated prairie region. A double-phase sampling approach is used which consists of first making a total census of wetlands using Landsat data, and then adjusting the Landsat results on the basis of samples derived from high resolution aircraft data. The method is relatively simple to use and has general applicability for estimating habitat features not consistently detectable or resolvable on Landsat imagery because their size range includes features less than the resolution capability of the satellite's sensor.

Gilmer, D. S.; Work, E. A.,Jr.; Colwell, J. E.; Rebel, D. L.

1980-01-01

279

Water-management model in Florida from LANDSAT-1 data  

NASA Technical Reports Server (NTRS)

A prototype data acquisition and dissemination network and its effectiveness in improving and/or solving hydrologic problems in southern Florida are evaluated. The network utilized LANDSAT MSS imagery and in situ monitoring by LANDSAT-DCS. Results show water level and rain fall measurements were collected and disseminated in less than two hours, a significant improvement over conventional methods which took up to two months. Improved network performance has also aided the development of water budgets and water distribution to the people, funa, and flora in the area. Imagery from LANDSAT was also found to enhance the utility of ground measurements.

Higer, A. L.; Cordes, E. H.; Coker, A. E.; Rogers, R. H.

1975-01-01

280

Quality Assessment of Landsat Surface Reflectance Products Using MODIS Data  

NASA Technical Reports Server (NTRS)

Surface reflectance adjusted for atmospheric effects is a primary input for land cover change detection and for developing many higher level surface geophysical parameters. With the development of automated atmospheric correction algorithms, it is now feasible to produce large quantities of surface reflectance products using Landsat images. Validation of these products requires in situ measurements, which either do not exist or are difficult to obtain for most Landsat images. The surface reflectance products derived using data acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS), however, have been validated more comprehensively. Because the MODIS on the Terra platform and the Landsat 7 are only half an hour apart following the same orbit, and each of the 6 Landsat spectral bands overlaps with a MODIS band, good agreements between MODIS and Landsat surface reflectance values can be considered indicators of the reliability of the Landsat products, while disagreements may suggest potential quality problems that need to be further investigated. Here we develop a system called Landsat-MODIS Consistency Checking System (LMCCS). This system automatically matches Landsat data with MODIS observations acquired on the same date over the same locations and uses them to calculate a set of agreement metrics. To maximize its portability, Java and open-source libraries were used in developing this system, and object-oriented programming (OOP) principles were followed to make it more flexible for future expansion. As a highly automated system designed to run as a stand-alone package or as a component of other Landsat data processing systems, this system can be used to assess the quality of essentially every Landsat surface reflectance image where spatially and temporally matching MODIS data are available. The effectiveness of this system was demonstrated using it to assess preliminary surface reflectance products derived using the Global Land Survey (GLS) Landsat images for the 2000 epoch. As surface reflectance likely will be a standard product for future Landsat missions, the approach developed in this study can be adapted as an operational quality assessment system for those missions.

Feng, Min; Huang, Chengquan; Channan, Saurabh; Vermote, Eric; Masek, Jeffrey G.; Townshend, John R.

2012-01-01

281

Landsat ecosystem disturbance adaptive processing system (LEDAPS) algorithm description  

USGS Publications Warehouse

The Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) software was originally developed by the National Aeronautics and Space Administration–Goddard Space Flight Center and the University of Maryland to produce top-of-atmosphere reflectance from LandsatThematic Mapper and Enhanced Thematic Mapper Plus Level 1 digital numbers and to apply atmospheric corrections to generate a surface-reflectance product.The U.S. Geological Survey (USGS) has adopted the LEDAPS algorithm for producing the Landsat Surface Reflectance Climate Data Record.This report discusses the LEDAPS algorithm, which was implemented by the USGS.

Schmidt, Gail; Jenkerson, Calli; Masek, Jeffrey; Vermote, Eric; Gao, Feng

2013-01-01

282

Impact of overlay metrology on design rule tolerance and shrinkability  

NASA Astrophysics Data System (ADS)

Design rule development for next technology generations depends on the progress in the optical and mechanical properties of steppers and photomasks. For two basic types of design rules: those that define minimum critical dimensions (CD, line and space), and those that define overlay/enclosure (OL) between layers, the shrinkpaths with technology nodes are generally unrelated. The min CD rules are dictated by stepper resolution limits and mask minimum features, the overlay rules - by the respective mechanical tolerances of the printing hardware. However, successful shrinks of design databases to the subsequent technology nodes require that all the design rules be scaled, preferably by the same factor. In this work, we first discuss the impact of the different types of rules on the layout architecture. We then show how one derives OL design rules from alignment tolerances. One method is based on the Lynch numbers (LN), corresponding to the misalignment budget ensuring that the OL yield loss is no more than 0.5% per mask level. However, LN"s are not directly measured in the fab. An alternative method is based on the 3s misregistration error. We demonstrate that these two methods show similar results for several types of masks and steppers. Finally, we show how the trend of overlay tolerance (OL) improvement compares with the trend of min feature size (CD) reduction. The data shows an offset between the OL and the CD trends amounting to 14 nm for the 45 nm technology node. This offset, which we call the overlay tolerance gap, means that enclosure rules would, in general, scale at a slower pace compared to the rules dictated by the linear CD shrink. One should note that the OL tolerance is influenced by matching of reticles and steppers and can be improved by the rework of wafers in line. In summary, we discuss theoretical and manufacturing-related aspects of overlay metrology, to advance design rule shrinks aligned with technology roadmap.

Balasinski, A.; Walker, A. J.

2005-05-01

283

Information expectations from Landsat-D  

NASA Technical Reports Server (NTRS)

The first satellite of the Landsat-D Project is to be launched in the third quarter of 1982 with a second satellite to be prepared for launch 12 to 15 months later. Both spacecraft are to include the familiar Multispectral Scanner (MSS) and the advanced multispectral scanner called the Thematic Mapper (TM). The ground data processing system for the MSS data is to be ready to produce 200 scenes a day in 1982. The data processing systems for the TM are to be fully operational at the 50 to 100 scenes a day level in early 1985. The fabrication of the system components has proceeded well in recent months, and integration of the total system is under way. The procedures for processing the data and meeting specifications are nearly completed for the MSS and are outlined in detail for the TM. An outline of an investigation program stressing systems performance has been developed for the period 1982 to 1985.

Salomonson, V. V.; Williams, D. L.; Barker, J. L.

1981-01-01

284

Sampling Landsat classifications for crop area estimation  

NASA Technical Reports Server (NTRS)

An investigation was conducted to evaluate the effect of several sampling alternatives on the accuracy of crop area estimates made from classification of Landsat Multispectral Scanner (MSS) data. The specific objective was to assess the precision and the bias associated with alternative sampling schemes involving different numbers of several sampling unit sizes. The estimates achieved using the 5 by 6 nm segments were found to have the least precision of any sampling scheme tested. The estimates become more precise as the segment size decreases and more segments are taken. The precision of the 5 by 6 nm segments was significantly less than that of the pixel samples. None of the sampling schemes was significantly biased on the average, and none of the average estimates differed significantly from the population parameter. The maximum absolute deviation, however, was directly related to sampling unit size and should be considered in selection of a sampling unit.

Hixson, M. M.; Davis, B. J.; Bauer, M. E.

1981-01-01

285

CROP type analysis using Landsat digital data  

NASA Technical Reports Server (NTRS)

Classification and statistical sampling techniques for crop type discrimination using Landsat digital data have been developed by the University of California in cooperation with NASA and the California Department of Water Resources. Ratioed bands (MSS 7/5 and 5/4) and a sun-angle corrected Euclidean albedo band were prepared from data for the Sacramento Valley for five different dates. The test area was stratified into general crop groupings based on the particular patterns of irrigation timing for each crop. Data classified within each stratum were used to produce a crop type map. Comparison with ground data indicates that certain crops and crop groups are discernable. Small grains and rice are easily identifiable, as are deciduous fruit varieties as a group. However, it is not feasible to separate various fruit and nut varieties, or separate vegetable crops with these techniques at present.

Brown, C. E.; Thomas, R. W.; Wall, S. L.

1981-01-01

286

Monitoring tropical vegetation succession with LANDSAT data  

NASA Technical Reports Server (NTRS)

The shadowing problem, which is endemic to the use of LANDSAT in tropical areas, and the ability to model changes over space and through time are problems to be addressed when monitoring tropical vegetation succession. Application of a trend surface analysis model to major land cover classes in a mountainous region of the Phillipines shows that the spatial modeling of radiance values can provide a useful approach to tropical rain forest succession monitoring. Results indicate shadowing effects may be due primarily to local variations in the spectral responses. These variations can be compensated for through the decomposition of the spatial variation in both elevation and MSS data. Using the model to estimate both elevation and spectral terrain surface as a posteriori inputs in the classification process leads to improved classification accuracy for vegetation of cover of this type. Spatial patterns depicted by the MSS data reflect the measurement of responses to spatial processes acting at several scales.

Robinson, V. B. (principal investigator)

1983-01-01

287

Landsat-5 Thematic Mapper outgassing effects  

USGS Publications Warehouse

A periodic 3% to 5% variation in detector response affecting both image and internal calibrator (IC) data has been observed in bands 5 and 7 of the Landsat-5 Thematic Mapper. The source for this variation is thought to be an interference effect due to buildup of an ice-like contaminant film on a ZnSe window, covered with an antireflective coating (ARC), of the cooled dewar containing these detectors. Periodic warming of the dewar is required in order to remove the contaminant and restore detector response to an uncontaminated level. These effects in the IC data have been characterized over four individual outgassing cycles using thin-film models to estimate transmittance of the window/ARC and ARC/contaminant film stack throughout the instrument lifetime. Based on the results obtained from this modeling, a lookup table procedure has been implemented that provides correction factors to improve the calibration accuracy of bands 5 and 7 by approximately 5%.

Helder, D. L.; Micijevic, E.

2004-01-01

288

A LANDSAT digital image rectification system  

NASA Technical Reports Server (NTRS)

DIRS is a digital image rectification system for the geometric correction of LANDSAT multispectral scanner digital image data. DIRS removes spatial distortions from the data and brings it into conformance with the Universal Transverse Mercator (UTM) map projection. Scene data in the form of landmarks are used to drive the geometric correction algorithms. Two dimensional least squares polynominal and spacecraft attitude modeling techniques for geometric mapping are provided. Entire scenes or selected quadrilaterals may be rectified. Resampling through nearest neighbor or cubic convolution at user designated intervals is available. The output products are in the form of digital tape in band interleaved, single band or CCT format in a rotated UTM projection. The system was designed and implemented on large scale IBM 360 computers.

Vanwie, P.; Stein, M.

1976-01-01

289

Evaluation of reforested areas using LANDSAT imagery  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. Visual and automatic interpretation of LANDSAT imagery was used to classify the general Pinus and Eucalyptus according to their age and species. A methodology was derived, based on training areas, to define the legend and spectral characteristics of the analyzed classes. Imager analysis of the training areas show that Pinus taeda is separable from the other Pinus species based on JM distance measurement. No difference of JM measurements was observed among Eucalyptus species. Two classes of Eucalyptus were separated according to their ages: those under and those over two years of age. Channel 6 and 7 were suitable for the discrimination of the reforested classes. Channel 5 was efficient to separated reforested areas from nonforested targets in the region. The automatic analysis shows the highest classification precision was obtained for Eucalyptus over two years of age (95.12 percent).

Dejesusparada, N. (principal investigator); Filho, P. H.; Shimabukuro, Y. E.

1978-01-01

290

LANDSAT D local user terminal study  

NASA Technical Reports Server (NTRS)

The effect of the changes incorporated in the LANDSAT D system on the ability of a local user terminal to receive, record and process data in real time was studied. Alternate solutions to the problems raised by these changes were evaluated. A loading analysis was performed in order to determine the quantities of data that a local user terminal (LUT) would be interested in receiving and processing. The number of bits in an MSS and a TM scene were calculated along with the number of scenes per day that an LUT might require for processing. These then combined to a total number of processed bits/day for an LUT as a function of sensor and coverage circle radius.

Alexander, L.; Louie, M.; Spencer, R.; Stow, W. K.

1976-01-01

291

Water quality mapping using Landsat TM imagery  

NASA Astrophysics Data System (ADS)

Environmental monitoring through the method of traditional ship sampling is time consuming and requires a high survey cost. The objective of this study is to evaluate the feasibility of Landsat TM imagery for total suspended solids (TSS) mapping using a newly developed algorithm over Penang Island. The study area is the seawater region around Penang Island, Malaysia. Water samples were collected during a 3-hour period simultaneously with the satellite image acquisition and later analyzed in the laboratory above the study area. The samples locations were determined using a handheld GPS. The satellite image was geometrically corrected using the second order polynomial transformation. The satellite image also was atmospheric corrected by using ATCOR2 image processing software. The digital numbers for each band corresponding to the sea-truth locations were extracted and then converted into reflectance values for calibration of the water quality algorithm. The proposed algorithm is based on the reflectance model that is a function of the inherent optical properties of water, which can be related to its constituent's concentrations. The generated algorithm was developed for three visible wavelenghts, red, green and blue for this study. Results indicate that the proposed developed algorithm was superior based on the correlation coefficient (R) and root-mean-square deviation (RMS) values. Finally the proposed algorithm was used for TSS mapping at Penang Island, Malaysia. The generated TSS map was colour-coded for visual interpretation and image smoothing was performed on the map to remove random noise. This preliminary study has produced a promising result. This study indicates that the empirical algorithm is suitable for TSS mapping around Penang Island by using satellite Landsat TM data.

Lim, H. S.; Matjafri, M. Z.; Abdullah, K.; Alias, A. N.; Wong, C. J.; Mustapha-Rosli, M. R.; Mohd Saleh, N.

2009-05-01

292

Comparing EO-1-Hyperions spectral resolution to Landsat  

NSDL National Science Digital Library

The Landsat system covers 7 spectral bands (of which six are shown here) while the Hyperion instrument records data in 220 bands from 353 nanometers to 2577 nanometers. This animation shows how they stack up.

Bridgman, Tom; Ungar, Stephen; Ong, Lawrence

2001-04-09

293

Crop classification using airborne radar and Landsat data  

NASA Technical Reports Server (NTRS)

NASA 13.3 GHz airborne radar data from a soil moisture measurement analysis is used to investigate the statistical nature of the radar backscattering coefficient for bare ground and three different crop types, and to evaluate the crop classification rates using Landsat data alone or combined with the airborne survey. The scatterometer was a fan-beam Doppler system, VV polarized, and is considered only for 50 deg angles of incidence. A total of 36 fields were covered a week apart by the aircraft and Landsat, and Rayleigh statistics were used in the frequency averaging to eliminate fluctuations due to random fluctuations. Within-field variances were calculated for the Landsat and the radar data and used to design optimum crop classification procedures. The Landsat Band 4 readings were 67% accurate, and an increase in accuracy of 10% was achieved by the addition of the radar data.

Ulaby, F. T.; Li, R. Y.; Shanmugan, K. S.

1982-01-01

294

Area estimation of crops by digital analysis of Landsat data  

NASA Technical Reports Server (NTRS)

The study for which the results are presented had these objectives: (1) to use Landsat data and computer-implemented pattern recognition to classify the major crops from regions encompassing different climates, soils, and crops; (2) to estimate crop areas for counties and states by using crop identification data obtained from the Landsat identifications; and (3) to evaluate the accuracy, precision, and timeliness of crop area estimates obtained from Landsat data. The paper describes the method of developing the training statistics and evaluating the classification accuracy. Landsat MSS data were adequate to accurately identify wheat in Kansas; corn and soybean estimates for Indiana were less accurate. Systematic sampling of entire counties made possible by computer classification methods resulted in very precise area estimates at county, district, and state levels.

Bauer, M. E.; Hixson, M. M.; Davis, B. J.

1978-01-01

295

Crop classification with a Landsat/radar sensor combination  

NASA Technical Reports Server (NTRS)

A combined Landsat/radar approach to classification of remotely sensed data, with emphasis on crops, was undertaken. Radar data were obtained by microwave radar spectrometers over fields near Eudora, Kansas and Landsat image data were obtained for the same test site. After Landsat digital images were registered and test-cells extracted, a comparable set of radar image pixels were simulated to match the Landsat pixels. The combined data set is then used for classification, and the results are examined with the best combination of sensor variables identified. Finally, the usefulness of radar in a simulated cloud-cover situation is demonstrated. The major conclusion derived from this study is that the combination of radar/optical sensors is superior to either one alone.

Li, R. Y.; Ulaby, F. T.; Eyton, J. R.

1980-01-01

296

Estimating Acreage by Double Sampling Using Landsat Data.  

National Technical Information Service (NTIS)

Double sampling techniques employing LANDSAT data for estimating the acreage of corn and soybeans was investigated and evaluated. The evaluation was based on estimated costs and correlations between two existing procedures having differing cost/variance c...

F. Pont H. Horwitz R. Kauth

1982-01-01

297

LANDSAT data for state planning. [of transportation for Georgia  

NASA Technical Reports Server (NTRS)

The results of an effort to generate and apply automated classification of LANDSAT digital data to state of Georgia problems are presented. This phase centers on an analysis of the usefulness of LANDSAT digital data to provide land-use data for transportation planning. Hall County, Georgia was chosen as a test site because it is part of a seventeen county area for which the Georgia Department of Transportation is currently designing a Transportation Planning Land-Use Simulation Model. The land-cover information derived from this study was compared to several other existing sources of land-use data for Hall County and input into this simulation. The results indicate that there is difficulty comparing LANDSAT derived land-cover information with previous land-use information since the LANDSAT data are acquired on an acre by acre grid basis while all previous land-use surveys for Hall County used land-use data on a parcel basis.

Faust, N. L.; Spann, G. W.

1975-01-01

298

Landsat's Role in Ecological Applications of Remote Sensing  

NSDL National Science Digital Library

This peer-reviewed resource from Bioscience is about the unique role of Landsat in remote sensing. Remote sensing, geographic information systems, and modeling have combined to produce a virtual explosion of growth in ecological investigations and applications that are explicitly spatial and temporal. Of all remotely sensed data, those acquired by Landsat sensors have played the most pivotal role in spatial and temporal scaling. Modern terrestrial ecology relies on remote sensing for modeling biogeochemical cycles and for characterizing land cover, vegetation biophysical attributes, forest structure, and fragmentation in relation to biodiversity. Given the more than 30-year record of Landsat data, mapping land and vegetation cover change and using the derived surfaces in ecological models is becoming commonplace. In this article, we summarize this large body of work, highlighting the unique role of Landsat.

WARREN B. COHEN and SAMUEL N. GOWARD (;)

2004-06-01

299

Full scale LANDSAT-D antenna pattern measurements  

NASA Technical Reports Server (NTRS)

The design verification of the LANDSAT-D antenna subsystem is addressed. In particular, the analysis of the antenna radiation patterns utilizing a full scale mockup of the LANDSAT-D satellite is discussed. Test antennas included two S-Band shaped beam antennas, two S-Band omni unit radiators (to operate in array), a GPS antenna, an X-Band shaped beam antenna, and one S-Band high-gain parabolic antenna.

1979-01-01

300

Remote sensing: Physical principles, sensors and products, and the LANDSAT  

NASA Technical Reports Server (NTRS)

Techniques of data acquisition by remote sensing are introduced in this teaching aid. The properties of the elements involved (radiant energy, topograph, atmospheric attenuation, surfaces, and sensors) are covered. Radiometers, photography, scanners, and radar are described as well as their products. Aspects of the LANDSAT system examined include the characteristics of the satellite and its orbit, the multispectral band scanner, and the return beam vidicon. Pixels (picture elements), pattern registration, and the characteristics, reception, and processing of LANDSAT imagery are also considered.

Dejesusparada, N. (principal investigator); Steffen, C. A.; Lorenzzetti, J. A.; Stech, J. L.; Desouza, R. C. M.

1981-01-01

301

Hydrography synthesis using LANDSAT remote sensing and the SCS models  

NASA Technical Reports Server (NTRS)

The land cover requirements of the Soil Conservation Service (SCS) Model used for hydrograph synthesis in urban areas were modified to be LANDSAT compatible. The Curve Numbers obtained with these alternate land cover categories compare well with those obtained in published example problems using the conventional categories. Emergency spillway hydrographs and synthetic flood frequency flows computed for a 21.1 sq. mi. test area showed excellent agreement between the conventional aerial photo-based and the Landsat-based SCS approaches.

Ragan, R. M.; Jackson, T. J.

1976-01-01

302

Landsat and Earth Systems Science: Development of Terrestrial Monitoring  

Microsoft Academic Search

One of the major catalysts leading to the development of the global-scale Earth Systems Science concept, the International Geosphere-Biosphere Program, and the U.S. Global Change Research Program were the unique views of Earth provided by Landsat sensors over the past 25 years. This paper ad- dresses Landsat's contributions in the Earth Systems Science arena. Early successes in observing the Earth's

Samuel N. Goward; Darrel L. Williams

1997-01-01

303

History of Remote Sensing: Landsat's Thematic Mapper (TM)  

NSDL National Science Digital Library

The Landsat Thematic Mapper is a multispectral imaging sensor added to Landsats 4 and later. This site uses text, photographs, tables, and diagrams to explain how the Thematic Mapper works and the advantages of sensing radiation in wavelengths other than those normally visible to the human eye. It is part of NASA's Remote Sensing Tutorial and links to the rest of the tutorial are provided.

304

Analysis of the private market for LANDSAT products and applications  

NASA Technical Reports Server (NTRS)

The private sector was examined and evaluated to develop base line strategies and mechanisms for its increased utilization of LANDSAT (and future satellite) technologies as both consumer and producer of products and services. Methodologies used to assess the digital analysis service and national mapping industries are described. Private sector users in business and industry are identified and the potential U.S. industry role in the foreign LANDSAT market is considered.

1981-01-01

305

Application of LANDSAT images in the Minas Gerais tectonic division  

NASA Technical Reports Server (NTRS)

The interpretation of LANDSAT data for a regional geological investigation of Brazil is provided. Radar imagery, aerial photographs and aeromagnetic maps were also used. Automatic interpretation, using LANDSAT OCT's was carried out by the 1-100 equipment. As a primary result a tectonic map was obtained, at 1:1,000,000 scale, of an area of about 143,000 square kilometers, in the central portion of Minas Gerais and Eastern Goias States, known as regions potentially rich in mineral resources.

Dacunha, R. P.; Demattos, J. T.

1978-01-01

306

LANDSAT-4 multispectral scanner (MSS) subsystem radiometric characterization  

NASA Technical Reports Server (NTRS)

The multispectral band scanner (mass) and its spectral characteristics are described and methods are given for relating video digital levels on computer compatible tapes to radiance into the sensor. Topics covered include prelaunch calibration procedures and postlaunch radiometric processng. Examples of current data resident on the MSS image processing system are included. The MSS on LANDSAT 4 is compared with the scanners on earlier LANDSAT satellites.

Alford, W. (editor); Barker, J. (editor); Clark, B. P.; Dasgupta, R.

1983-01-01

307

Analysis of Landsat for monitoring vegetables in New York mucklands  

NASA Technical Reports Server (NTRS)

This pilot study assessed the feasibility of relying on Landsat multispectral scanner data for inventorying vegetables grown in mucklands,in variably shaped, variably sized fields. Classification of muckland vegetables using a Euclidean distance classifier and a parallelepiped classifier was performed with reasonable accuracy (generally over 60 percent) based on only one date of Landsat data. Prior canonical and principal component analyses did not improve the classification accuracy but did reduce the dimensionality of the data.

Zhu, M. H.; Yan, S. Y.; Philipson, W. R.; Yen, C. C.; Philpot, W. D.

1983-01-01

308

A comparative study of overlay generation methods in bite mark analysis  

PubMed Central

Aim: To evaluate the best method of overlay generation out of the three methods, i.e., manual, photocopying, and computer assisted method. Materials and Methods: Impressions of maxillary and mandibular arches of 25 individuals participating in the study were made and dental study models were prepared. Overlay production was done by manual, photocopying, and computer assisted methods. Finally, the overlays obtained by each method were compared. Results: Kruskal Wallis ANOVA H test was used for the comparison of manual, photocopying, and computer assisted overlay generation methods. H value being highest in case of computer assisted overlays, thus, making it the best method of overlay generation out of the three methods. Conclusion: We conclude that the method of computer assisted overlay generation is the best among the three methods used in our study.

Khatri, Mihir; Daniel, Mariappan Jonathan; Srinivasan, Subramanian Vasudevan

2013-01-01

309

An Overview of the Landsat Data Continuity Mission  

NASA Technical Reports Server (NTRS)

The advent of the Landsat Data Continuity Mission (LDCM), currently with a launch readiness date of December, 2012, will see evolutionary changes in the Landsat data products available from the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center. The USGS initiated a revolution in 2009 when EROS began distributing Landsat data products at no cost to requestors in contrast to the past practice of charging the cost of fulfilling a request; that is, charging $600 per Landsat scene. To implement this drastic change, EROS terminated data processing options for requestors and began to produce all data products using a consistent processing recipe. EROS plans to continue this practice for the LDCM and will required new algorithms to process data from the LDCM sensors. All previous Landsat satellites flew multispectral scanners to collect image data of the global land surface. Additionally, Landsats 4, 5, and 7 flew sensors that acquired imagery for both reflective spectral bands and a single thermal band. In contrast, the LDCM will carry two pushbroom sensors; the Operational Land Imager (OLI) for reflective spectral bands and the Thermal InfraRed Sensor (TIRS) for two thermal bands. EROS is developing the ground data processing system that will both calibrate and correct the data from the thousands of detectors employed by the pushbroom sensors and that will also combine the data from the two sensors to create a single data product with registered data for all of the OLI and TIRS bands.

Irons, James R.; Dwyer, John L.

2010-01-01

310

AN ELECTRICAL RESISTANCE MEASURING DEVICE FOR DETERMINING THE THICKNESS OF A WELDED MONEL OVERLAY ON CARBON STEEL  

Microsoft Academic Search

The development and calibration of a device which measures the thickness ; of a welded monel overlay on carbon steel are described. The device measures the ; electrical resistance between two points on the surface of the overlay, which is ; correlated with the overlay thickness. The device provides a measure of the ; average overlay thickness existing in an

Lind

1960-01-01

311

Flutter Analysis of the Shuttle Tile Overlay Repair Concept  

NASA Technical Reports Server (NTRS)

The Space Shuttle tile overlay repair concept, developed at the NASA Johnson Space Center, is designed for on-orbit installation over an area of damaged tile to permit safe re-entry. The thin flexible plate is placed over the damaged area and secured to tile at discreet points around its perimeter. A series of flutter analyses were performed to determine if the onset of flutter met the required safety margins. Normal vibration modes of the panel, obtained from a simplified structural analysis of the installed concept, were combined with a series of aerodynamic analyses of increasing levels of fidelity in terms of modeling the flow physics to determine the onset of flutter. Results from these analyses indicate that it is unlikely that the overlay installed at body point 1800 will flutter during re-entry.

Bey, Kim S.; Scott, Robert C.; Bartels, Robert E.; Waters, William A.; Chen, Roger

2007-01-01

312

Daylighting design overlays for equidistant sun-path projections  

SciTech Connect

Projections of the Sun's daily and seasonal paths frequently are used to solve building design problems involving site obstructions and shading of fenestration. In the United States, equidistant projections are perhaps the most widely used (compared to other sunpath projections) because of the commercial availability of a complete set of sun-path diagrams for a range of useful latitudes. This paper describes the development of a set of overlays designed for use with sun-path projections to predict illumination on any building surface throughout the year for standard climatological conditions. Illumination is calculated for clear and overcast skies and for direct sunlight using algorithms recommended by the Commission Internationale de l'Eclairage (CIE). Values for illumination incident upon the surface, as well as transmitted through single and double glazing, can be calculated. Similar overlays for solar radiation are being developed.

Selkowitz, S.

1981-08-01

313

Ion beam mixing of titanium overlayers with hydroxyapaptite substrates  

SciTech Connect

The mixing of titanium overlayers with hydroxyapatite (HA) substrates via ion irradiation has been demonstrated. Analysis via secondary ion mass spectroscopy (SIMS) indicates an interfacial broadening of titanium and calcium of the implanted sample compared to that of the unimplanted sample. Attendant to the observed ion beam mixing of titanium into the HA, the oxygen signal of the titanium overlayer increases as a result of ion irradiation. It is supposed that this change is evident of diffusion through the metal layer and possibly from titania formation at the free surface and perovskite formation at the film/substrate interface. This possibility is consistent with thermodynamic predictions. Additionally, the force required to separate the film from the substrate increased as a result of ion irradiation, validating the continued study of ion beam processing of Ti/HA systems towards the improvement of long term fixation of implant devices.

Levine, T.E. [Cornell Univ., Ithaca, NY (United States). Dept. of Materials Science and Engineering; Nastasi, M. [Los Alamos National Lab., NM (United States); Alford, T.L.; Suchicital, C.; Russell, S.; Luptak, K.; Pizziconi, V.; Mayer, J.W. [Arizona State Univ., Tempe, AZ (United States)

1995-01-01

314

Defect formation dynamics during CdTe overlayer growth  

NASA Astrophysics Data System (ADS)

The presence of atomic-scale defects at multilayer interfaces significantly degrades performance in CdTe-based photovoltaic technologies. The ability to accurately predict and understand defect formation mechanisms during overlayer growth is, therefore, a rational approach for improving the efficiencies of CdTe materials. In this work, we utilize a recently developed CdTe bond-order potential (BOP) to enable accurate molecular dynamics (MD) simulations for predicting defect formation during multilayer growth. A detailed comparison of our MD simulations to high-resolution transmission electron microscopy experiments verifies the accuracy and predictive power of our approach. Our simulations further indicate that island growth can reduce the lattice mismatch induced defects. These results highlight the use of predictive MD simulations to gain new insight into defect reduction in CdTe overlayers, which directly addresses efforts to improve these materials.

Chavez, J. J.; Ward, D. K.; Wong, B. M.; Doty, F. P.; Cruz-Campa, J. L.; Nielson, G. N.; Gupta, V. P.; Zubia, D.; McClure, J.; Zhou, X. W.

2012-06-01

315

Overlay of Arbitrarily Shaped Material Regions onto Hexahedral Meshes  

NASA Astrophysics Data System (ADS)

In Eulerian and ALE hydrodynamics simulations, zones contain a mixture of materials when mesh boundaries do not conform with material boundaries. In problem generation at initial time, three-dimensional regions containing assigned material properties are specified as shapes, with a limited number of parameters describing the volume of the region. In the shape overlay procedure, the mesh is initialized with a background material in each zone, and the background material is replaced with the assigned material within each region. Zones intersecting the surface of the shape become mixed, and the essential requirement is to compute the volume of intersection between the shape and each zone on the mesh. We demonstrate, using meshes containing up to 10^6 nonorthogonal, nonuniform hexahedral zones, that shape overlays are a practical means of accurately and efficiently generating hydrodynamics problems on currently available workstations.

Grandy, Jeffrey

1997-08-01

316

Modeling the dynamical interaction between epidemics on overlay networks  

NASA Astrophysics Data System (ADS)

Epidemics seldom occur as isolated phenomena. Typically, two or more viral agents spread within the same host population and may interact dynamically with each other. We present a general model where two viral agents interact via an immunity mechanism as they propagate simultaneously on two networks connecting the same set of nodes. By exploiting a correspondence between the propagation dynamics and a dynamical process performing progressive network generation, we develop an analytical approach that accurately captures the dynamical interaction between epidemics on overlay networks. The formalism allows for overlay networks with arbitrary joint degree distribution and overlap. To illustrate the versatility of our approach, we consider a hypothetical delayed intervention scenario in which an immunizing agent is disseminated in a host population to hinder the propagation of an undesirable agent (e.g., the spread of preventive information in the context of an emerging infectious disease).

Marceau, Vincent; Noël, Pierre-André; Hébert-Dufresne, Laurent; Allard, Antoine; Dubé, Louis J.

2011-08-01

317

Are Virtualized Overlay Networks Too Much of a Good Thing?  

Microsoft Academic Search

Themajorityofrecenthigh-proflleworkinpeer-to-peernet- workshasapproachedtheproblemoflocationbyabstractingoverobject lookup services. Namespace virtualization in the overlay layer provides load balance andprovableboundsonlatency at lowcosts. We contend that namespace virtualization comes at a signiflcant cost for applications that naturally describe their data sets in a hierarchical manner.Opportunitiesforenhancingbrowsing,prefetchingande-cient attribute-based searches are lost. A hierarchy exposes relationships be- tween items near to each other in the topology; virtualization of the namespace

Peter J. Keleher; Bobby Bhattacharjee; Bujor D. Silaghi

2002-01-01

318

Ultrasonic Evaluation of Two Dissimilar Metal Weld Overlay Specimens  

Microsoft Academic Search

Two dissimilar metal weld (DMW) pipe-to-nozzle specimens were implanted with thermal fatigue cracks in the 13% to 90% through-wall depth range. The specimens were ultrasonically evaluated with phased-array probes having center frequencies of 0.8, 1.0, 1.5, and 2.0 megahertz (MHz). An Alloy 82\\/182 weld overlay (WOL) was applied and the specimens were ultrasonically re-evaluated for flaw detection and characterization. The

Susan L. Crawford; Anthony D. Cinson; Matthew S. Prowant; Traci L. Moran; Michael T. Anderson

2012-01-01

319

Topologically-Aware Overlay Construction and Server Selection  

Microsoft Academic Search

A number of large-scale distributed Internet applications could potentially benefit from some level of knowledge about the relative proximity between its participating host nodes. For example, the perfor- mance of large overlay networks could be improved if the application-level connectivity between the nodes in these networks is congruent with the un- derlying IP-level topology. Similarly, in the case of replicated

Sylvia Ratnasamy; Mark Handley; Richard M. Karp; Scott Shenker

2002-01-01

320

Improving graph-based overlay routing in delay tolerant networks  

Microsoft Academic Search

We present CGR-EB, a modification of, and extension to, the Contact Graph Routing (CGR) protocol — a forwarding mechanism for interplanetary communication. CGR-EB enables graph-based overlay routing for a variety of networks, including those using vehicular assets as data mules. It improves CGR by storing end-to-end message paths and encoding these paths, and the sub-graphs that spawned them, with the

Edward J. Birrane

2011-01-01

321

Service overlay networks: SLAs, QoS, and bandwidth provisioning  

Microsoft Academic Search

We advocate the notion of service overlay network (SON) as an effective means to address some of the issues, in particular, end-to-end quality of service (QoS), plaguing the current Internet, and to facilitate the creation and deployment of value-added Internet services such as VoIP, Video-on-Demand, and other emerging QoS-sensitive services. The SON purchases bandwidth with certain QoS guarantees from the

Zhenhai Duan; Zhi-Li Zhang; Yiwei Thomas Hou

2003-01-01

322

Service Overlay Networks: SLAs, QoS and Bandwidth Provisioning  

Microsoft Academic Search

We advocate the notion of service overlay network (SON) as an effective means to address some of the issues, in par- ticular, end-to-end QoS, plaguing the current Internet, and to facilitate the creation and deployment of value-added In- ternet services such as VoIP, Video-on-Demand, and other emerging QoS-sensitive services. A SON purchases band- width with certain QoS guarantees from individual

Zhenhai Duan; Zhi-li Zhang; Yiwei Thomas Hou

2002-01-01

323

Shielding turbine blades from cvitation: Experiments with polymer overlays  

SciTech Connect

Cavitation damage to hydroelectric machinery produces one of the most prevalent maintenance problems at any hydro plant. Damage to the turbine runner blades, draft tube liner and discharge ring, and sometimes even the runner hub can require extensive welding repair. Typically, each unit develops its own cavitation characteristics that continue throughout the life of the machine. The traditional cavitation repair method is to gouge out the damaged material, then refill the void with a stainless steel. This method is costly and time-consuming, may cause blade distortion, and may result in galvanic corrosion when the stainless steel is applied to carbon steel base materials. What's more, this gouging and filling at temperatures between 2,200 and 2.300[degrees]F within a tenth of a square inch may cause residual stresses in the parent material. One strategy for limiting cavitation effects on turbine components is to overlay the original material with a protective layer. This protective coating will absorb the cavitation load, or at least a portion of it, thus limiting further damage to repaired areas. Typically, an overlay consists of a 1/32-inch or 1/16-inch layer of polymer material (either epoxies or ceramics) and a thin adhesive that bonds the polymer to the turbine steel. A cavitation-induced shock (energy) wave propagates through the polymer material and either reflects or transmits into the steel. (The relative acoustic impedances of the two materials determine whether the shock wave travels into the turbine steel or reflects back through the polymer.) For the overlay to be effective, the shock wave must be reflected, attenuated, or dispersed. typical overlay materials do not reflect, attenuate, or disperse the cavitation shock wave. Polycarbonates, with their unique energy dissipation capabilities, are a good candidate for a protective turbine blade coating.

Armentrout, T.B. (Army Corps of Engineers, The Dalles, OR (United States))

1993-05-01

324

Studies of the Si(111) surface with various Al overlayers  

Microsoft Academic Search

The electronic structure of the Si(111) surface with Al overlayers has been investigated by the self-consistent pseudopotential method for three different Al chemisorption sites. The geometries are a onefold coordinated covalent site, and two other geometries which correspond to threefold coordinated ionic sites with different Al-Si bond lengths. The electronic energy bands, local densities of states, and charge distributions for

H. I. Zhang; M. Schlüter

1978-01-01

325

ROMA: Reliable Overlay Multicast with Loosely Coupled TCP Connections  

Microsoft Academic Search

We consider the problem of architecting a reliable content delivery system across an overlay network using TCP connections as the transport primitive. We first argue that natural designs based on store-and-forward principles that tightly couple TCP connections at intermediate end-systems impose fundamen- tal performance limitations, such as dragging down all transfer rates in the system to the rate of the

Gu.-In. Kwon; John W. Byers

2004-01-01

326

Multicast Routing in Structured Overlays and Hybrid Networks  

NASA Astrophysics Data System (ADS)

Key-based routing has enabled efficient group communication on the application or service middleware layer, stimulated by the need of applications to access multicast. These developments follow a continuous debate about network layer multicast that had lasted for about 30 years history of the Internet. The IP host group model today still faces a strongly divergent state of deployment. In this chapter, we first review the key concepts of multicast and broadcast data distribution on structured overlays. Second, we perform a comprehensive theoretical analysis examining the different distribution trees constructed on top of a key-based routing layer. Characteristic performance measures of the multicast approaches are compared in detail and major structural differences are identified. Overlay multicast overcomes deployment problems on the price of a performance penalty. Hybrid approaches, which dynamically combine multicast in overlay and underlay, adaptively optimize group communication. We discuss current schemes along with its integration in common multicast routing protocols in the third part of this chapter. Finally, we reconsider and enhance approaches to a common API for group communication, which serves the requirements of data distribution and maintenance for multicast and broadcast on a middleware abstraction layer, and in particular facilitates hybrid multicast schemes.

Wählisch, Matthias; Schmidt, Thomas C.

327

Hg binding on Pd binary alloys and overlays  

SciTech Connect

The vast majority of the mercury released from coal combustion is elemental mercury. Noble metals such as Pd, Au, Ag, and Cu have been proposed to capture elemental mercury. Density functional theory calculations are carried out to investigate mercury interactions with Pd binary alloys and overlays in addition to pure Pd, Au, Ag, and Cu surfaces using a projected augmented wave method with the Perdew-Wang generalized 0 gradient approximation. It has been determined that Pd has the highest mercury binding energy in comparison to other noble metals. In addition, Pd is found to be the primary surface atom responsible for improving the interaction of mercury with the surface atoms in both Pd binary alloys and overlays. Deposition of Pd overlays on Au and Ag enhance the reactivity of the surface by shifting the d-states of surface atoms up in energy. Strong mercury binding causes a significant overlap between the s- and p-states of Pd and the d-state of Mercury.

Sasmaz, E.; Aboud, S.; Wilcox, J. [Stanford University, Stanford, CA (United States). School of Earth Science

2009-05-15

328

An Overlapping Structured P2P for REIK Overlay Network  

NASA Astrophysics Data System (ADS)

REIK is based on a ring which embedded an inverse Kautz digraph, to enable multi-path P2P routing. It has the constant degree and the logarithmic diameter DHT scheme with constant congestion and Byzantine fault tolerance. However, REIK did not consider the interconnection of many independent smaller networks. In this paper, we propose a new approach to build overlay network, OLS-REIK which is an overlapping structured P2P for REIK overlay network. It is a more flexible interconnecting different REIK network. Peers can belong to several rings, allowing this interconnection. By connecting smaller structured overlay networks in an unstructured way, it provides a cost effective alternative to hierarchical structured P2P systems requiring costly merging. Routing of lookup messages is performed as in REIK within one ring, but a peer belonging to several rings forwards the request to the different rings it belongs to. Furthermore a small number of across point is enough to ensure a high exhaustiveness level.

Liu, Wenjun; Song, Jingjing; Yu, Jiguo

329

Landsat classification of Argentina summer crops  

NASA Technical Reports Server (NTRS)

A Landsat MSS and TM classification approach based on three features derived from the greenness profile has proved very effective in separating and identifying corn, soybeans, and other ground cover classes in the U.S. The objective of this study is to investigate the separation of summer crops in Argentina, one of the most important commodity exporters, using the same greenness profile features that have proved effective in the U.S. Corn Belt. The area chosen for study is a more complex cropping practice area located in the north-west corner of Buenos Aires province in Pampa Humeda, where corn, soybean, sorghum, sunflower, and pastures are cultivated. It is shown that the profile features can provide very effective separation, except in the case of corn from sorghum. Separation between corn and soybeans was found to be greater than in the U.S. This study suggests that the automatic, unsupervised classification approach developed in the U.S., with relatively minor modification, can be used for summer crop area estimation in Argentina.

Badhwar, G. D.; Gargantini, C. E.; Redondo, F. V.

1987-01-01

330

Science Writer's Guide to Landsat 7  

NASA Technical Reports Server (NTRS)

The Earth Observing System (EOS), the centerpiece of NASA's Earth science program, is a suite of spacecraft and interdisciplinary science investigations dedicated to advancing our understanding of global change. The flagship EOS satellite, Terra (formerly EOS AM-1), scheduled for launch in July 1999, will provide key measurements of the physical and radiative properties of clouds; air-land and air-sea exchanges of energy, carbon, and water; trace gases; and volcanoes. Flying in formation with Terra, Landsat 7 will make global high spatial resolution measurements of land surface and surrounding coastal regions. Other upcoming EOS missions and instruments include QuikSCAT, to collect sea surface wind data; the Stratospheric Gas and Aerosol Experiment (SAGE III), to create global profiles of key atmospheric gases; and the Active Cavity Radiometer Irradiance Monitors (ACRIM) to measure the energy output of the Sun. The second of the major, multi-instrument EOS platforms, PM-1, is scheduled for launch in 2000. Interdisciplinary research projects sponsored by EOS use specific Earth science data sets for a broader investigation into the function of Earth systems. Current EOS research spans a wide range of sciences, including atmospheric chemistry, hydrology, land use, and marine ecosystems. The EOS program has been managed since 1990 by the Goddard Space Flight Center in Greenbelt, Md., for NASA's Office of Earth Science in Washington, D. C. Additional information on the program can be found on the EOS Project Science Office Web site (http://eospso.gsfc.nasa.gov).

1999-01-01

331

LITHOLOGIC MAPPING USING LANDSAT THEMATIC MAPPER DATA.  

USGS Publications Warehouse

The paper is in abstract form. It discusses the Landsat-4 Thematic Mapper (TM), with its new near infrared bands centered at 1. 65 mu m and 2. 20 mu m and spatial resolution of 30 m, which has been used to distinguish rocks containing minerals having ferric-iron absorption bands in the visible and near-infrared and Al-O and CO//3 absorption bands in the 2. 1-2. 4 mu m regions. On the basis of characteristic absorption bands, digitally processed TM data were used to differentiate vegetated from non-vegetated areas, limonitic from nonlimonitic rocks, rocks containing minerals having absorption bands in the near-infrared region from rocks lacking the infrared absorption bands. Specific minerals were detected in both the humid eastern and semi-arid western United States. The absorption bands in the near-infrared region were used to detect kaolinite in open-pit exposures of a kaolin mining district near Macon, Georgia; calcium carbonate in the beach sands along the east coast of Florida; and kaolinite, alunite, jarosite, sericite and gypsum in natural exposures near Boulder City, Nevada.

Podwysocki, M. H.; Salisbury, J. W.; Jones, O. D.; Mimms, D. L.

1983-01-01

332

Lithologic mapping using Landsat thematic mapper data  

USGS Publications Warehouse

The Landsat-4 Thematic Mapper (TM), with its new near infrared bands centered at 1.65 ?m and 2.20 ?m and spatial resolution of 30 m has been used to distinguish rocks containing minerals having ferric-iron absorption bands in the visible and near-infrared and Al-O- and CO3 absorption bands in the 2.1-2.4 ?m regions. On the basis of characteristic absorption bands, digitally processed TM data were used to differentiate vegetated from non-vegetated areas, limonitic from nonlimonitic rocks, rocks containing minerals having absorption bands in the near-infrared region from rocks lacking infrared absorption bands. Specific minerals were detected in both the humid eastern and semi-arid western United States. The absorption bands in the near-infrared region were used to detect kaolinite in open-pit exposures of a kaolin mining district near Macon, Georgia; calcium carbonate in the back sands along the east coast of Floridia; and kaolinite, alunite, jarosite, sericite and gypsum in natural exposures near Boulder City, Nevada. These results show that the additional spectral bands in the near-infrared region and increased spatial resolution of the Thematic Mapper provide a valuable tool for distinguishing several significant geologic materials not distinguishable from space using previous imaging systems. They also show that TM data can be successfully used in a variety of geologic environments.

Podwysocki, M. H.; Salisbury, J. W.; Jones, O. D.; Mimms, D. L.

1983-01-01

333

Wrench faulting using seismic and Landsat  

SciTech Connect

Two high-multiplicity seismic profiles demonstrate the compressional nature of the faulting along the Double Mountain Lineament in northeast Garza County in the Permian basin. NASA high-altitude aircraft imagery using Landsat parameters delineate the traces of these faults on the surface. The drainage system also defines the fault traces by following the zones of fracture and weakness in the Permian and Triassic outcrops. A north-south seismic profile crosses the Double Mountain lineament (P Shear), defining two thrust faults, two high-angle reverse faults and a pop-up block (flow structure). NASA high-altitude imagery and stream drainage indicate the traces of these faults. The pattern developed fits the definition of left lateral wrench faulting. Overlying carbonate shelf margins are developed above the underlying structure, which further enhances the structural interpretation. An east-west seismic profile 3 mi southeast of the north-south profile again defines the Double Mountain Lineament or P Shear and the associated faulting. A 1-mi wide pop-up block with a high angle reverse fault on both sides demonstrates the compressional nature of the faulting, and the high-altitude imagery delineates the surface traces of the faults. This structure has been drilled with several Stawn and Ellenburger producers, confirming the seismic and surface interpretations in the subsurface.

Bolden, G.P.

1987-05-01

334

Improvement in absolute calibration accuracy of Landsat-5 TM with Landsat-7 ETM+ data  

USGS Publications Warehouse

The ability to detect and quantify changes in the Earth's environment depends on satellites sensors that can provide calibrated, consistent measurements of Earth's surface features through time. A critical step in this process is to put image data from subsequent generations of sensors onto a common radiometric scale. To evaluate Landsat-5 (L5) Thematic Mapper's (TM) utility in this role, image pairs from the L5 TM and Landsat-7 (L7) Enhanced Thematic Mapper Plus (ETM+) sensors were compared. This approach involves comparison of surface observations based on image statistics from large common areas observed eight days apart by the two sensors. The results indicate a significant improvement in the consistency of L5 TM data with respect to L7 ETM+ data, achieved using a revised Look-Up-Table (LUT) procedure as opposed to the historical Internal Calibrator (IC) procedure previously used in the L5 TM product generation system. The average percent difference in reflectance estimates obtained from the L5 TM agree with those from the L7 ETM+ in the Visible and Near Infrared (VNIR) bands to within four percent and in the Short Wave Infrared (SWIR) bands to within six percent.

Chander, G.; Markham, B. L.; Micijevic, E.; Teillet, P. M.; Helder, D. L.

2005-01-01

335

Rice crop monitoring with multitemporal MODIS-Landsat data fusion  

NASA Astrophysics Data System (ADS)

Rice is one of the most important cereal crops in the world and is the major crop in Taiwan. However, it is a challenge because rice fields are generally small and fragmental, while crop mapping requires information of crop phenology associating with the high spatiotemporal resolution of remote-sensing data. This problem can be partially overcome by a spatiotemporal fusion to create a new dataset that has a better spatiotemporal resolution. In this study, the Moderate Resolution Imaging Spectroradiometer (MODIS) and Landsat imageries were used because MODIS data, which a spatial resolution of land bands of 500 m and temporal resolution of 1?2 days, were able to achieve the phenological information of rice crops at a large region; while Landsat data demonstrate the effectiveness to collectively map small patches of crop fields at the subnational level due to its spatial resolution of 30 m. However, the temporal resolution of Landsat data is lower (16 days), making it difficult to investigate temporal responses of crop phenology from rice fields. The main objective of this study was to take into account of advantages of MODIS and Landsat imageries to generate a synthetic dataset at Landsat spatial resolution and MODIS temporal resolution for rice crop mapping in Taiwan. The methodology comprised five steps: (1) satellite data for 2011 were pre-processed to account for geometric and radiometric correction of MODIS and Landsat data, (2) MODIS-Landsat data fusion using the Spatial Temporal Adaptive Fusion Model (STARFM), (3) construct the smooth time-series Normalized Difference Vegetation Index (NDVI) data using wavelet transform, (4) rice crop classification using phenological information of crop phenology, and (5) accuracy assessment. The data fusion results for day of year (DOY) 153 were compared with the reference Landsat data (DOY 153) indicated a close correlation (R2 = 0.81). The phenology-based classification results compared with the ground reference data revealed close agreement between these two datasets. The overall accuracy and Kappa coefficient were 82% and 0.75, respectively. The relationship between the MODIS-derived rice areas and those from the government's rice area statistics at the district level was examined, reaffirming a strong correlation between the two datasets with R2 > 0.9. This study demonstrates advantages of MODIS-Landsat data fusion for rice crop mapping in Taiwan. Such an approach used in this study could be applied for other regions to map small patches of crops at a subnational scale.

Chen, Cheng-Ru; Chen, Chi-Farn; Son, Nguyen-Thanh

2014-05-01

336

Subsetting and Formatting Landsat-7 LOR ETM+ and Data Products  

NASA Technical Reports Server (NTRS)

The Landsat-7 Processing System (LPS) processes Landsat-7 Enhanced Thematic Mapper (ETM+) instrument data into large, contiguous segments called "subintervals" and stores them in Level OR (LOR) data files. The LPS processed subinterval products must be subsetted and reformatted before the Level I processing systems can ingest them. The initial full subintervals produced by the LPS are stored mainly in HDF Earth Observing System (HDF-EOS) format which is an extension to the Hierarchical Data Format (HDF). The final LOR products are stored in native HDF format. Primarily the EOS Core System (ECS) and alternately the DAAC Emergency System (DES) subset the subinterval data for the operational Landsat-7 data processing systems. The HDF and HDF-EOS application programming interfaces (APIs) can be used for extensive data subsetting and data reorganization. A stand-alone subsetter tool has been developed which is based on some of the DES code. This tool makes use of the HDF and HDFEOS APIs to perform Landsat-7 LOR product subsetting and demonstrates how HDF and HDFEOS can be used for creating various configurations of full LOR products. How these APIs can be used to efficiently subset, format, and organize Landsat-7 LOR data as demonstrated by the subsetter tool and the DES is discussed.

Reid, Michael R.

2000-01-01

337

Global land information system (GLIS) access to worldwide Landsat data  

USGS Publications Warehouse

The Landsat Technical Working Group (LTWG) and the Landsat Ground Station Operations Working Group (LGSOWG) have encouraged Landsat receiving stations around the world to share information about their data holdings through the exchange of metadata records. Receiving stations forward their metadata records to the U.S. Geological Survey's EROS Data Center (EDC) on a quarterly basis. The EDC maintains the records for each station, coordinates changes to the database, and provides metadata to the stations as requested. The result is a comprehensive international database listing most of the world's Landsat data acquisitions This exchange of information began in the early 1980's with the inclusion in the EDC database os scenes acquired by a receiving station in Italy. Through the years other stations have agreed to participate; currently ten of the seventeen stations actively share their metadata records. Coverage maps have been generated to depict the status of the database. The Worldwide Landsat database is also available though the Global Land Information System (GLIS).

Smith, Timothy B.; Goodale, Katherine L.

1993-01-01

338

Characterizing the LANDSAT Global Long-Term Data Record  

NASA Technical Reports Server (NTRS)

The effects of global climate change are fast becoming politically, sociologically, and personally important: increasing storm frequency and intensity, lengthening cycles of drought and flood, expanding desertification and soil salinization. A vital asset in the analysis of climate change on a global basis is the 34-year record of Landsat imagery. In recognition of its increasing importance, a detailed analysis of the Landsat observation coverage within the US archive was commissioned. Results to date indicate some unexpected gaps in the US-held archive. Fortunately, throughout the Landsat program, data have been downlinked routinely to International Cooperator (IC) ground stations for archival, processing, and distribution. These IC data could be combined with the current US holdings to build a nearly global, annual observation record over this 34-year period. Today, we have inadequate information as to which scenes are available from which IC archives. Our best estimate is that there are over four million digital scenes in the IC archives, compared with the nearly two million scenes held in the US archive. This vast pool of Landsat observations needs to be accurately documented, via metadata, to determine the existence of complementary scenes and to characterize the potential scope of the global Landsat observation record. Of course, knowing the extent and completeness of the data record is but the first step. It will be necessary to assure that the data record is easy to use, internally consistent in terms of calibration and data format, and fully accessible in order to fully realize its potential.

Arvidson, T.; Goward, S. N.; Williams, D. L.

2006-01-01

339

Overlay control strategy for 45/32nm RD and production ramp up  

NASA Astrophysics Data System (ADS)

The tight overlay budgets required for 45nm and beyond makes overlay control a very important topic. High order overlay control (HOC) is becoming an essential methodology to remove the immersion induced overlay signatures. However, to implement the high order control into dynamic APC system requires FA infrastructure modification and a stable mass production environment. How to achieve the overlay requirement before the APC-HOC system becomes available is important for RD environment and for product early ramp up phase. In this paper authors would like to demonstrate a field-by-field correction (FxFc) or correction per exposure (CPE) methodology to improve high order overlay signature without changing current APC-linear control system.

Yu, Tuan-Yen; Lin, Jun-Hung; Huang, Yong-Fa; Chen, Chien-Hao; Yu, Chun-Chi; Huang, Chin-Chou Kevin; Huang, Chien-Jen; Tien, David

2010-03-01

340

Sampling strategy: optimization and correction for high-order overlay control for 45nm process node  

NASA Astrophysics Data System (ADS)

The tight overlay budgets required for 45nm and beyond make overlay control a very important topic. With the adoption of immersion lithography, the incremental complexity brings much more difficulty to analyzing the source of variation and optimizing the sampling strategy. In this paper, there will be a discussion about how the use of an advanced sampling methodology and strategy can help to overcome this overlay control problem and insure sufficient overlay information to be captured for effective production lot excursion detection as well as rework decision making. There will also be a demonstration of the different correction methodologies to improve overlay control for dual-stage systems in order to maximize the productivity benef its with minimal impact to overlay performance.

Hsueh, Bo Yun; Huang, George K. C.; Yu, Chun-Chi; Huang, Chin-Chou Kevin; Huang, Chien-Jen; Manka, James R.; Tien, David

2009-03-01

341

Innovative fast technique for overlay accuracy estimation using archer self calibration (ASC)  

NASA Astrophysics Data System (ADS)

As overlay margins shrink for advanced process nodes, a key overlay metrology challenge is finding the measurement conditions which optimize the yield for every device and layer. Ideally, this setup should be found in-line during the lithography measurements step. Moreover, the overlay measurement must have excellent correlation to the device electrical behavior. This requirement makes the measurement conditions selection even more challenging since it requires information about the response of both the metrology target and device to different process variations. In this work a comprehensive solution for overlay metrology accuracy, used by UMC, is described. This solution ranks the different measurement setups by their accuracy, using Qmerit, as reported by the Archer 500. This ranking was verified to match device overlay using electrical tests. Moreover, the use of Archer Self Calibration (ASC) allows further improvement of overlay measurement accuracy.

Hsu, Simon C. C.; Chen, Charlie; Yu, Chun Chi; Pai, Yuan Chi; Amit, Eran; Yap, Lipkong; Itzkovich, Tal; Tien, David; Huang, Eros; Kuo, Kelly T. L.; Amir, Nuriel

2014-04-01

342

Development and validation of an improved algorithm for overlaying flexible molecules.  

PubMed

A program for overlaying multiple flexible molecules has been developed. Candidate overlays are generated by a novel fingerprint algorithm, scored on three objective functions (union volume, hydrogen-bond match, and hydrophobic match), and ranked by constrained Pareto ranking. A diverse subset of the best ranked solutions is chosen using an overlay-dissimilarity metric. If necessary, the solutions can be optimised. A multi-objective genetic algorithm can be used to find additional overlays with a given mapping of chemical features but different ligand conformations. The fingerprint algorithm may also be used to produce constrained overlays, in which user-specified chemical groups are forced to be superimposed. The program has been tested on several sets of ligands, for each of which the true overlay is known from protein-ligand crystal structures. Both objective and subjective success criteria indicate that good results are obtained on the majority of these sets. PMID:22538643

Taylor, Robin; Cole, Jason C; Cosgrove, David A; Gardiner, Eleanor J; Gillet, Valerie J; Korb, Oliver

2012-04-01

343

Deforestation Planning for Cattle Grazing in Amazon Basin Using LANDSAT Data.  

National Technical Information Service (NTIS)

The author has identified the following significant results. This research did not show the total potential of the LANDSAT system, but tried to open up new research aspects for the utilization of LANDSAT data in natural resource control. Results obtained ...

N. de Jesus Parada A. P. dos Santos E. M. L. de Morais Novo

1978-01-01

344

Eliminating Topographic Illumination Effects from Landsat Imagery  

NASA Astrophysics Data System (ADS)

The solar illumination across a single satellite image is variable due to tree cover, slope, aspect and flux density. This makes it difficult to discern differences in land cover. In order to extract different land cover types from multispectral moderate resolution imagery, many techniques (mainly supervised and unsupervised classifications) have been used. These methods often perform adequately, but often must ignore finer resolution phenomena. Supervised classification suffers from this flaw, while unsupervised classification also often detects large differences in solar illumination as different classes. This makes lower flux density vegetation classify differently than illuminated vegetation, even of the same species. Existing topographic correction methods may overcorrect, rely on site-specific empirical terms or require data often unavailable in areas of interest (Kane et al. 2008). We present a new technique to remove topographic illumination effects with available global data and spectral unmixing. It uses a three endmember mixing model of substrate, vegetation, and dark (SVD) on Landsat imagery (Small 2004). The dark fraction is then plotted against a simulated incidence angle image derived from ASTER GDEM data to see the incidence angle-dark fraction space. This technique minimizes the trend between solar illumination values calculated from ASTER GDEM and the SVD dark fraction. This trend is then minimized to the nominal flux density of a level surface. With this minimization, the fraction estimates are reduced on sun-facing slopes and increased on sun-backing slopes. The resulting image can then be used to study variations in land cover without the overprinting of topographic shadow or variations in solar flux.

Gale, J.; Small, C.

2013-12-01

345

Landsat Witnesses the Destruction of Mesopotamian Ecosystem  

NSDL National Science Digital Library

In one of the greatest ecological disasters of our time, the ancient marshlands of Mesopotamia are systematically being converted to dry salt flats as a result of human mismanagement of the regions water resources.Landsat satellite imagery reveals that in the last 10 years, wetlands that once covered as much as 20,000 square km in parts of Iraq and Iran have been reduced to a small fraction of their original size. The authors of a new report released by the United Nations Environment Programmes (UNEP) at the 11th Stockholm Water Symposium on August 13, 2001, warn that the marshlands could completely disappear within the next 3-5 years unless dramatic steps are taken immediately to reverse the damage being done. The UNEP Executive Director described the wetlands condition as a major environmental catastrophe that will be remembered as one of humanitys worst engineered disasters. He noted that the tragic loss of this rare wetland has occurred in approximately the same period since world leaders pledged to safeguard the environment at the United Nations Conference on Environment and Development (the Earth Summit) held in Rio de Janeiro in 1992. Regarded by historians as one of the cradles of civilization, the Mesopotamian Fertile Crescent has supported Marsh Arab society for millennia. But through the damming and siphoning off of waters from the Tigris and Euphrates Rivers, the countries of Iran, Iraq, Turkey, and Syria have decimated the ecosystem and, with it, a culture rooted in the dawn of human history (dating back to ancient Sumeria about 5,000 years ago).

Perkins, Lori; Partow, Hassan

2001-08-02

346

Defending P2Ps from Overlay Flooding-based DDoS  

Microsoft Academic Search

A flooding-based search mechanism is often used in un- structured P2P systems. Although a flooding-based search mechanism is simple and easy to implement, it is vulnerable to overlay distributed denial-of-service (DDoS) attacks. Most pre- vious security techniques protect networks from network-layer DDoS attacks, but cannot be applied to overlay DDoS attacks. Overlay flooding-based DDoS attacks can be more damaging in

Yunhao Liu; Xiaomei Liu; Chen Wang; Li Xiao

2007-01-01

347

mTreebone: A Collaborative Tree-Mesh Overlay Network for Multicast Video Streaming  

Microsoft Academic Search

Recently, application-layer overlay networks have been suggested as a promising solution for live video streaming over the Internet. To organize a multicast overlay, a natural structure is a tree, which, however, is known vulnerable to end-hosts dynamics. Data-driven approaches address this problem by employing a mesh structure, which enables data exchanges among multiple neighbors, and thus, greatly improves the overlay

Feng Wang; Yongqiang Xiong; Jiangchuan Liu

2010-01-01

348

Content-Based Peer-to-Peer Network Overlay for Full-Text Federated Search  

Microsoft Academic Search

Peer-to-peer network overlays have mostly been designed to support search over document names, identifiers, or keywords from a small or controlled vocabulary. In this paper we propose a content-based P2P network overlay for full-text federated search over heterogeneous, open-domain contents. Local algorithms are developed to dynamically construct a network overlay with content-based locality and content-based small-world properties. Experimental results using

Jie Lu; Jamie Callan

2007-01-01

349

Mean offset optimization for multi-patterning overlay using Monte Carlo simulation method  

NASA Astrophysics Data System (ADS)

The overlay performance and alignment strategy optimization for a triple patterning (LELELE) were studied based on the Monte Carlo simulation method. The simulated results show that all of the combined or worst case overlay, alignment strategy, mean target of the upper level, and mean tolerance of the lower level are dependent on the means of the lower level. A dynamic mean control method is proposed to be integrated into the APC system to improve the overlay performance.

Wang, Wenhui; Cui, Liping; Sun, Lei; Kim, Ryoung-Han

2014-04-01

350

Urban change detection procedures using Landsat digital data  

NASA Technical Reports Server (NTRS)

Landsat multispectral scanner data was applied to an urban change detection problem in Denver, CO. A dichotomous key yielding ten stages of residential development at the urban fringe was developed. This heuristic model allowed one to identify certain stages of development which are difficult to detect when performing digital change detection using Landsat data. The stages of development were evaluated in terms of their spectral and derived textural characteristics. Landsat band 5 (0.6-0.7 micron) and texture data produced change detection maps which were approximately 81 percent accurate. Results indicated that the stage of development and the spectral/textural features affect the change in the spectral values used for change detection. These preliminary findings will hopefully prove valuable for improved change detection at the urban fringe.

Jensen, J. R.; Toll, D. L.

1982-01-01

351

Crop classification using airborne radar and LANDSAT data. [Colby, Kansas  

NASA Technical Reports Server (NTRS)

Airborne radar data acquired with a 13.3 GHz scatterometer over a test-site near Colby, Kansas were used to investigate the statistical properties of the scattering coefficient of three types of vegetation cover and of bare soil. A statistical model for radar data was developed that incorporates signal-fading and natural within-field variabilities. Estimates of the within-field and between-field coefficients of variation were obtained for each cover-type and compared with similar quantities derived from LANDSAT images of the same fields. The classification accuracy provided by LANDSAT alone, radar alone, and both sensors combined was investigated. The results indicate that the addition of radar to LANDSAT improves the classification accuracy by about 10; percentage-points when the classification is performed on a pixel basis and by about 15 points when performed on a field-average basis.

Ulaby, F. T. (principal investigator); Li, R. Y.; Shanmugam, K. S.

1981-01-01

352

Spatial and spectral simulation of LANDSAT images of agricultural areas  

NASA Technical Reports Server (NTRS)

A LANDSAT scene simulation capability was developed to study the effects of small fields and misregistration on LANDSAT-based crop proportion estimation procedures. The simulation employs a pattern of ground polygons each with a crop ID, planting date, and scale factor. Historical greenness/brightness crop development profiles generate the mean signal values for each polygon. Historical within-field covariances add texture to pixels in each polygon. The planting dates and scale factors create between-field/within-crop variation. Between field and crop variation is achieved by the above and crop profile differences. The LANDSAT point spread function is used to add correlation between nearby pixels. The next effect of the point spread function is to blur the image. Mixed pixels and misregistration are also simulated.

Pont, W. F., Jr. (principal investigator)

1982-01-01

353

Spatial and spectral simulation of Landsat images of agricultural areas  

NASA Technical Reports Server (NTRS)

A Landsat scene simulation capability was developed to study the effects of small fields and misregistration on Landsat-based crop proportion estimation procedures. The simulation employs a pattern of ground polygons each with a crop ID, planting date, and scale factor. Historical greenness/brightness crop development profiles generate the mean signal values for each polygon. Historical within-field covariances add texture to pixels in each polygon. The planting dates and scale factors create between-field/within-crop variation. Between field and crop variation is achieved by the above and crop profile differences. The Landsat point spread function is used to add correlation between nearby pixels. The next effect of the point spread function is to blur the image. Mixed pixels and misregistration are also simulated. Previously announced in STAR as N82-32813

Pont, W. F., Jr.

1982-01-01

354

Cumulus cloud properties derived using Landsat satellite data  

NASA Technical Reports Server (NTRS)

Landsat Multispectral Scanner (MSS) digital data are used to remotely sense cumulus cloud properties such as cloud fraction and cloud reflectance, along with the distribution of cloud number and cloud fraction as a function of cloud size. The analysis is carried out for four cumulus fields covering regions approximately 150 km square. Results for these initial cloud fields indicate that: (1) the common intuitive model of clouds as nearly uniform reflecting surfaces is a poor representation of cumulus clouds, (2) the cumulus clouds were often multicelled, even for clouds as small as 1 km in diameter, (3) cloud fractional coverage derived using a simple reflectance threshold is sensitive to the chosen threshold even for 57-meter resolution Landsat data, (4) the sensitivity of cloud fraction to changes in satellite sensor resolution is less sensitive than suggested theoretically, and (5) the Landsat derived cloud size distributions show encouraging similarities among the cloud fields examined.

Wielicki, B. A.; Welch, R. M.

1986-01-01

355

LANDSAT application of remote sensing to shoreline-form analysis  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. LANDSAT imagery of the southern end of Assateague Island, Virginia, was enlarged to 1:80,000 and compared with high altitude (1:130,000) and low altitude (1:24,000) aerial photography in an attempt to quantify change in land area over a nine month period. Change in area and configuration was found with LANDSAT and low altitude photography. Change in configuration, but no change in area was found with high altitude photography. Due to tidal differences at time of image obtention and lack of baseline data, the accuracy of the LANDSAT measurements could not be determined. They were consistent with the measurements from the low altitude photography.

Dolan, R.; Hayden, B.; Heywood, J. (principal investigators); Hewitt, C.; Michel, J.

1976-01-01

356

Impact of LANDSAT MSS sensor differences on change detection analysis  

NASA Technical Reports Server (NTRS)

Some 512 by 512 pixel subwindows for simultaneously acquired scene pairs obtained by LANDSAT 2,3 and 4 multispectral band scanners were coregistered using LANDSAT 4 scenes as the base to which the other images were registered. Scattergrams between the coregistered scenes (a form of contingency analysis) were used to radiometrically compare data from the various sensors. Mode values were derived and used to visually fit a linear regression. Root mean square errors of the registration varied between .1 and 1.5 pixels. There appear to be no major problem preventing the use of LANDSAT 4 MSS with previous MSS sensors for change detection, provided the noise interference can be removed or minimized. Data normalizations for change detection should be based on the data rather than solely on calibration information. This allows simultaneous normalization of the atmosphere as well as the radiometry.

Likens, W. C.; Wrigley, R. C.

1983-01-01

357

Two-way communication and analysis program on LANDSAT  

NASA Technical Reports Server (NTRS)

Community workshops, field visits, telephone surveys, and other research reveals that professionals at the substate level are interested in and open to consideration of LANDSAT as a planning and resource management tool, but are at the same time skeptical about some of the inherent problems with LANDSAT such as cost, resolution, frequency of coverage, and data continuity. The principal requirements for increasing the utilization of LANDSAT by potential substate users were identified and documented. Without a committment from the Federal Government for increased substrate utilization and the availability of trained professionals to meet the needs of a largely new user community, substrate activity is likely to remain at a minimum. Well conceived and well executed demonstration projects could play a critical role is shaping the technology's ability to be more sensitive to substate user needs and interests as well as validating the effectiveness of this data to a skeptical audience.

1983-01-01

358

Kerr Reservoir LANDSAT experiment analysis for March 1981  

NASA Technical Reports Server (NTRS)

LANDSAT radiance data were used in an experiment conducted on the waters of Kerr Reservoir to determine if reliable algorithms could be developed that relate water quality parameters to remotely sensed data. A mix of different types of algorithms using the LANDSAT bands was generated to provide a thorough understanding of the relationships among the data involved. Except for secchi depth, the study demonstrated that for the ranges measured, the algorithms that satisfactorily represented the data encompass a mix of linear and nonlinear forms using only one LANDSAT band. Ratioing techniques did not improve the results since the initial design of the experiment minimized the errors against which this procedure is effective. Good correlations were found for total suspended solids, iron, turbidity, and secchi depth. Marginal correlations were discovered for nitrate and tannin + lignin. Quantification maps of Kerr Reservoir are presented for many of the water quality parameters using the developed algorithms.

Lecroy, S. R. (principal investigator)

1982-01-01

359

Compensating process non-uniformity to improve wafer overlay by RegC  

NASA Astrophysics Data System (ADS)

The introduction of double and triple patterning tightened the Overlay current nodes' specifications across the industry to levels of 5nm and 3nm respectively. Overlay error is a combination of Intra-field and field-to-field errors. The Intra-field error includes several systematic signatures, such as overlay magnitude differences between X and Y axes, field center vs edge and more. The recent developments in scanner technology improved the intra-field Overlay to high orders. In this work we have quantified the state-of-the-art residual overlay errors and applied the RegC® (registration/overlay control) process, a new solution of deep sub-nanometer pattern shift, to further improve the overlay process control, in addition to the current lithography's state-of-the-art capabilities. As a result we managed to reduce the baseline overlay error by more than one nanometer and reduced systematic intrafield non-uniformities, by removing the 3 sigma difference between X and Y to zero. The combination of intra-field control by RegC® with high order correction per exposure (CPE) by the scanner provides a new era of overlay control required for the 2x and 1x multiple patterning processes.

Leray, Philippe; Cheng, Shaunee; Cohen, Avi; Graitzer, Erez; Dmitriev, Vladimir; Rehtan, Shiran; Wertsman, Nadav

2014-04-01

360

Infrared differential interference contrast microscopy for 3D interconnect overlay metrology.  

PubMed

One of the main challenges for 3D interconnect metrology of bonded wafers is measuring through opaque silicon wafers using conventional optical microscopy. We demonstrate here the use infrared microscopy, enhanced by implementing the differential interference contrast (DIC) technique, to measure the wafer bonding overlay. A pair of two dimensional symmetric overlay marks were processed at both the front and back sides of thinned wafers to evaluate the bonding overlay. A self-developed analysis algorithm and theoretical fitting model was used to map the overlay error between the bonded wafers and the interconnect structures. The measurement accuracy was found to be better than 1.0 micron. PMID:23938801

Ku, Yi-sha; Shyu, Deh-Ming; Lin, Yeou-Sung; Cho, Chia-Hung

2013-08-12

361

Radiometric calibration of the Landsat MSS sensor series  

USGS Publications Warehouse

Multispectral remote sensing of the Earth using Landsat sensors was ushered on July 23, 1972, with the launch of Landsat-1. Following that success, four more Landsat satellites were launched, and each of these carried the Multispectral Scanner System (MSS). These five sensors provided the only consistent multispectral space-based imagery of the Earth's surface from 1972 to 1982. This work focuses on developing both a consistent and absolute radiometric calibration of this sensor system. Cross-calibration of the MSS was performed through the use of pseudoinvariant calibration sites (PICSs). Since these sites have been shown to be stable for long periods of time, changes in MSS observations of these sites were attributed to changes in the sensors themselves. In addition, simultaneous data collections were available for some MSS sensor pairs, and these were also used for cross-calibration. Results indicated substantial differences existed between instruments, up to 16%, and these were reduced to 5% or less across all MSS sensors and bands. Lastly, this paper takes the calibration through the final step and places the MSS sensors on an absolute radiometric scale. The methodology used to achieve this was based on simultaneous data collections by the Landsat-5 MSS and Thematic Mapper (TM) instruments. Through analysis of image data from a PICS location and through compensating for the spectral differences between the two instruments, the Landsat-5 MSS sensor was placed on an absolute radiometric scale based on the Landsat-5 TM sensor. Uncertainties associated with this calibration are considered to be less than 5%.

Helder, Dennis L.; Karki, Sadhana; Bhatt, Rajendra; Micijevik, Esad; Aaron, David; Jasinski, Benjamin

2012-01-01

362

Mass balance investigation of alpine glaciers through LANDSAT TM data  

NASA Technical Reports Server (NTRS)

An analysis of LANDSAT Thematic Mapper (TM) data of the Pasterze Glacier and the Kleines Fleisskees in the Austrian Alps was undertaken and compared with meteorological data of nearby weather stations. Alpine or valley glaciers can be used to study regional and worldwide climate changes. Alpine glaciers respond relatively fast to a warming or cooling trend in temperature through an advance or a retreat of the terminus. In addition, the mass balance of the glacier is being affected. Last year two TM scenes of the Pasterze Glacier of Aug. 1984 and Aug. 1986 were used to study the difference in reflectance. This year, in addition to the scenes from last year, one MSS scene of Aug. 1976 and a TM scene from 1988 were examined for both the Pasterze Glacier and the Kleines Fleisskees. During the overpass of the LANDSAT on 6 Aug. 1988 ground truthing on the Pasterze Glacier was undertaken. The results indicate that there was considerable more reflectance in 1976 and 1984 than in 1986 and 1988. The climatological data of the weather stations Sonnblick and Rudolfshuette were examined and compared with the results found through the LANDSAT data. There were relations between the meteorological and LANDSAT data: the average temperature over the last 100 years showed an increase of .4 C, the snowfall was declining during the same time period but the overall precipitation did not reveal any significant change over the same period. With the use of an interactive image analysis computer, the LANDSAT scenes were studied. The terminus of the Pasterze Glacier retreated 348 m and the terminus of the Kleines Fleisskees 121 m since 1965. This approach using LANDSAT MSS and TM digital data in conjunction with meteorological data can be effectively used to monitor regional and worldwide climate changes.

Bayr, Klaus J.

1989-01-01

363

Prototyping Global Web Enabled Landsat Data Production, Distribution and Visualization  

NASA Astrophysics Data System (ADS)

The NASA funded Web-enabled Landsat Data (WELD) project is systematically generating 30m weekly, seasonal, monthly and annual composited Landsat mosaics of the conterminous United States and Alaska (http://weld.cr.usgs.gov/). The WELD products provide consistent data that are starting to be used for land management applications and to derive land cover as well as geophysical and biophysical products for assessment of surface dynamics and to study Earth system functioning. This paper describes the challenges in expanding this production and internet distribution and visualization to global scale. At global scale, the volume of Landsat data and the number of files become so large that they are awkward to work and become a type of "Big Data" although the products are sufficiently well structured for their management using database management tools. Prototyping efforts running a global version of the WELD code on the NASA Earth Exchange (NEX) high-performance supercomputing platform are presented. Global monthly WELD products generated in the Sinusoidal Projection in tiles nested to the MODIS Land product tiling scheme are illustrated and an intuitive what you see is what you get (WYSIWYG) global WELD product Internet distribution and visualization interface is showcased. The global availability of cloud-free Landsat Enhanced Thematic Mapper Plus (ETM+) and Thematic Mapper (TM) data and the monthly global probability of acquiring a cloud-free land surface observation for the two instruments independently and fused together are reported with recommendations for global Landsat processing of the 30m U.S. Landsat archive back to 1982.

Roy, D. P.; Kommareddy, I.; Kovalskyy, V.; Votava, P.; Nemani, R. R.; Ju, J.

2012-12-01

364

CROP CLASSIFICATION FOR THE NILO COELHO SCHEME BY USING LANDSAT TM IMAGES  

Microsoft Academic Search

In this paper were used Landsat TM images and supervised classification in order to distinguish crop areas and obtained the crop classification for the Nilo Coelho scheme. For land -use classification band 4, 5, 3 (Landsat TM) was assigned to Red Green Blue (RGB). A commercial software package (ERDAS Imagine v. 8.5) was available for the processing of the Landsat

EDWIN NOORDMAN; MAGNA SOELMA BEZERRA DE MOURA; MARCONI ANTÃO DOS SANTOS; MARIA DAS GRAÇAS; LOPES DOS SANTOS; HELIO LEANDRO LOPES

2003-01-01

365

Next Generation Landsat Products Delivered Using Virtual Globes and OGC Standard Services  

Microsoft Academic Search

The Landsat Data Continuity Mission (LDCM) is the next in the series of Landsat satellite missions and is tasked with the objective of delivering data acquired by the Operational Land Imager (OLI). The OLI instrument will provide data continuity to over 30 years of global multispectral data collected by the Landsat series of satellites. The U.S. Geological Survey Earth Resources

M. Neiers; J. Dwyer; S. Neiers

2008-01-01

366

Improved Landsat-based forest mapping in steep mountainous terrain using object-based classification  

Microsoft Academic Search

The accuracy of forest stand type maps derived from a Landsat Thematic Mapper (Landsat TM) image of a heterogeneous forest covering rugged terrain is generally low. Therefore, the first objective of this study was to assess whether topographic correction of TM bands and adding the digital elevation model (DEM) as additional band improves the accuracy of Landsat TM-based forest stand

Luuk K. A. Dorren; Bernhard Maier; Arie C. Seijmonsbergen

2003-01-01

367

Landsat change detection can aid in water quality monitoring  

NASA Technical Reports Server (NTRS)

Comparison between Landsat-1 and -2 imagery of Arkansas provided evidence of significant land use changes during the 1972-75 time period. Analysis of Arkansas historical water quality information has shown conclusively that whereas point source pollution generally can be detected by use of water quality data collected by state and federal agencies, sampling methodologies for nonpoint source contamination attributable to surface runoff are totally inadequate. The expensive undertaking of monitoring all nonpoint sources for numerous watersheds can be lessened by implementing Landsat change detection analyses.

Macdonald, H. C.; Steele, K. F.; Waite, W. P.; Shinn, M. R.

1977-01-01

368

Area estimation of forestlands in southwestern Michigan from LANDSAT imagery  

NASA Technical Reports Server (NTRS)

The accuracy of mapping and estimating the area of forestlands in southwestern Michigan from winter and fall LANDSAT images was evaluated. All omission and commission errors in the LANDSAT forest maps were identified and mapped through comparison with an existing detailed forest cover type map. Accuracies ranged from 74.0% to 98.5% and were higher for the winter imagery. Most errors (85%) occurred along the perimeter of forestlands and were less than 4 hectares (10 acres) and size. Other factors affecting interpretation are reported as well as time and image availability considerations.

Karteris, M. A.; Enslin, W. R.; Thiede, J.

1981-01-01

369

The use of temporal data in Landsat crop surveys  

NASA Technical Reports Server (NTRS)

Multidate Landsat imagery has been applied for crop identification purposes in Kern County, California. The county's arid climate provides complete sets of cloud-free imagery throughout the crop-growing season. Both manual and digital techniques are used to study the value of the data, and a semiautomated video system is used to extract densitometric data from Landsat transparencies. It is noted that temporal variations in single-date classification performance and increases in multidate performance are caused by the physiological and phenological differences between types of crops. These differences may be used to introduce crop calendar data into satellite crop surveys.

Tinney, L. R.

1977-01-01

370

Linear dimensionality of Landsat agricultural data with implications for classification  

NASA Technical Reports Server (NTRS)

A model for the Landsat multispectral scanner data, representing a generalization of the commonly used Gaussian model, has been formulated and analyzed. The model hypothesizes that the data for different crop types essentially lie on distinct hyperplanes in the feature space. Tests of this model reveal that: (1) the agricultural data from any single acquisition (i.e., four-channel) of Landsat are essentially two dimensional, regardless of the crop type; and (2) the data from different sites and different stages of crop development all lie on planes which are parallel. These findings have significant implications for data display, classification, feature extraction, and signature extension.

Wheeler, S. G.; Misra, P. N.; Holmes, Q. A.

1976-01-01

371

LANDSAT-D program. Volume 2: Ground segment  

NASA Technical Reports Server (NTRS)

Raw digital data, as received from the LANDSAT spacecraft, cannot generate images that meet specifications. Radiometric corrections must be made to compensate for aging and for differences in sensitivity among the instrument sensors. Geometric corrections must be made to compensate for off-nadir look angle, and to calculate spacecraft drift from its prescribed path. Corrections must also be made for look-angle jitter caused by vibrations induced by spacecraft equipment. The major components of the LANDSAT ground segment and their functions are discussed.

1984-01-01

372

Indicatrices of the earth's surface reflection from Landsat MSS data.  

PubMed

A method of obtaining an indicatrix or a scattering diagram of the earth's surface is developed. When we regard the earth's surface as a kind of irregular surface, the indicatrix of scattered radiation is a way of effective representation of its surface roughness. The indicatrices of radiation over the sands of a seashore, a downtown area of Tokyo, and some of its suburban areas are obtained from Landsat MSS data. The radiant intensity decreases within the range of 32 degrees to 65 degrees of scattering angles in accordance with the degree of urbanization. Experimental results obtained by a remote sensing simulator are compared with those of Landsat MSS data analysis. PMID:18200248

Okayama, H; Ogura, I

1983-11-15

373

LANDSAT-D data format control book. Volume 2: Telemetry  

NASA Technical Reports Server (NTRS)

The formats used for the transmission of LANDSAT-D and LANDSAT-D Prime spacecraft telemetry data through either the TDRS/GSTDN via the NASCOM Network to the CSF are described as well as the telemetry flow from the command and data handling subsystem, a telemetry list and telemetry matrix assignment for the mission and engineering formats. The on-board computer (OBC) controlled format and the dwell format are also discussed. The OBCs contribution to telemetry, and the format of the reports, are covered. The high rate data channel includes the payload correction data format, the narrowband tape recorder and the OBC dump formats.

Talipsky, R.

1982-01-01

374

Intraband radiometric performance of the Landsat Thematic Mappers.  

USGS Publications Warehouse

Radiometric characteristics have been examined of the Landsat-4 and Landsat-5 Thematic Mappers (TMs) that can be established without absolute calibration of spectral data. This analysis is based on radiometrically and geometrically raw (B-type) data of both uniform (flat-field) and high-contrast scenes. Subscenes selected for uniform radiance were used to characterized subtle radiometric differences and noise problems. Although the general performance of the Thematic Mappers is excellent, various anomalies that have a magnitude of a few digital levels (DN) or less are quantified. -from Authors

Kieffer, H. H.; Cook, D. A.; Eliason, E. M.; Eliason, P. T.

1985-01-01

375

Mapping wetland and forest landscapes in Siberia with Landsat data  

NASA Astrophysics Data System (ADS)

Landsat data availability provides opportunity for improving the knowledge of the Siberian ecosystems necessary for quantifying the response of the regional carbon cycle to the climate change. We developed a new wetland map based on Landsat data for whole West Siberia aiming at scaling up the methane emission observations. Mid-summer Landsat scenes were used in supervised classification method, based on ground truth data obtained during multiple field surveys. The method allows distinguishing following wetland types: pine-dwarf shrubs-sphagnum bogs or ryams, ridge-hollows complexes, shallow-water complexes, sedge-sphagnum poor fens, herbaceous-sphagnum poor fens, sedge-(moss) poor fens and fens, wooded swamps or sogra, palsa complexes. In our estimates wetlands cover 36% of the taiga area. Total methane emission from WS taiga mires is estimated as 3.6 TgC/yr,which is 77% larger as compared to the earlier estimate based on partial Landsat mapping combined with low resolution map due to higher fraction of fen area. We make an attempt to develop a forest typology system useful for a dynamic vegetation modeling and apply it to the analysis of the forest type distribution for several test areas in West and East Siberia, aiming at capability of mapping whole Siberian forests based on Landsat data. Test region locations are: two in West Siberian middle taiga (Laryegan and Nyagan), and one in East Siberia near Yakutsk. The ground truth data are based on analysis of the field survey, forest inventory data from the point of view of the successional forest type classification. Supervised classification was applied to the areas where ample ground truth and inventory data are available, using several limited area maps and vegetation survey. In Laryegan basin the upland forest areas are dominated (as climax forest species) by Scots pine on sandy soils and Siberian pine with presence of fir and spruce on the others. Those types are separable using Landsat spectral data alone. In the permafrost area around Yakutsk the most widespread succession type is birch to larch succession. Three stages of the birch to larch succession are detectable from Landsat image. When Landsat data is used in both West and East Siberia, distinction between deciduous broad-leaved species (birch, aspen, and willow) is difficult due to similarity in spectral signatures. Same problem exists for distinguishing between dark coniferous species (Siberian pine, fir and spruce). Forest classification can be improved by applying landscape type analysis, such as separation into floodplain, terrace, sloping hills.

Maksyutov, Shamil; Kleptsova, Irina; Glagolev, Mikhail; Sedykh, Vladimir; Kuzmenko, Ekaterina; Silaev, Anton; Frolov, Alexander; Nikolaeva, Svetlana; Fedorov, Alexander

2014-05-01

376

Natural resources research and development in Lesotho using LANDSAT imagery  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. A map of the drainage of the whole country to include at least third order streams was constructed from LANDSAT imagery. This was digitized and can be plotted at any required scale to provide base maps for other cartographic projects. A suite of programs for the interpretation of digital LANDSAT data is under development for a low cost programmable calculator. Initial output from these programs has proved to have better resolution and detail than the standard photographic products, and was to update the standard topographic map of a particular region.

Jackson, A. A. (principal investigator)

1976-01-01

377

An Illumination Correction ALgorithm on Landsat-TM Data  

NASA Technical Reports Server (NTRS)

In this paper, a new illumination correction model, the rotation model, is introduced. The model is based on the empirical correlation between reflectance and the illumination condition (IL). The model eliminates the dependency of reflectance on IL through rotating the data in IL-reflectance space. This model is compared with widely used cosine model and C model over a sample forest region. We found that the newly developed rotation model consistently performs best on both atmospheric uncorrected and corrected Landsat images. Index Terms Landsat, illumination correction, change detection, LEDAPS

Tan, Bin; Wolfe, Robert; Masek, Jeffrey; Gao, Feng; Vermote, Eric F.

2010-01-01

378

Detecting air pollution stress in southern California vegetation using Landsat Thematic Mapper band data  

SciTech Connect

Landsat Thematic Mapper (TM) and aircraft-borne Thematic Mapper simulator (TMS) data were collected over two areas of natural vegetation in southern California exposed to gradients of pollutant dose, particularly in photochemical oxidants: the coastal sage scrub of the Santa Monica Mountains in the Los Angeles basin, and the yellow pine forests in the southern Sierra Nevada. In both situations, natural variations in canopy closure, with subsequent exposure of understory elements (e.g.,rock or soil, chaparral, grasses, and herbs), were sufficient to cause changes in spectral variation that could obscure differences due to visible foliar injury symptoms observed in the field. TM or TMS data are therefore more likely to be successful in distinguishing pollution injury from background variation when homogeneous communities with closed canopies are subjected to more severe pollution-induced structural and/or compositional change. The present study helps to define the threshold level of vegetative injury detectable by TM data. 26 references.

Westman, W.E.; Price, C.V.

1988-09-01

379

Detecting air pollution stress in southern California vegetation using Landsat Thematic Mapper band data  

NASA Technical Reports Server (NTRS)

Landsat Thematic Mapper (TM) and aircraft-borne Thematic Mapper simulator (TMS) data were collected over two areas of natural vegetation in southern California exposed to gradients of pollutant dose, particularly in photochemical oxidants: the coastal sage scrub of the Santa Monica Mountains in the Los Angeles basin, and the yellow pine forests in the southern Sierra Nevada. In both situations, natural variations in canopy closure, with subsequent exposure of understory elements (e.g.,rock or soil, chaparral, grasses, and herbs), were sufficient to cause changes in spectral variation that could obscure differences due to visible foliar injury symptoms observed in the field. TM or TMS data are therefore more likely to be successful in distinguishing pollution injury from background variation when homogeneous communities with closed canopies are subjected to more severe pollution-induced structural and/or compositional change. The present study helps to define the threshold level of vegetative injury detectable by TM data.

Westman, Walter E.; Price, Curtis V.

1988-01-01

380

Characterization of wafer geometry and overlay error on silicon wafers with nonuniform stress  

NASA Astrophysics Data System (ADS)

Process-induced overlay errors are a growing problem in meeting the ever-tightening overlay requirements for integrated circuit production. Although uniform process-induced stress is easily corrected, nonuniform stress across the wafer is much more problematic, often resulting in noncorrectable overlay errors. Measurements of the wafer geometry of free, unchucked wafers give a powerful method for characterization of such nonuniform stress-induced wafer distortions. Wafer geometry data can be related to in-plane distortion of the wafer pulled flat by an exposure tool vacuum chuck, which in turn relates to overlay error. This paper will explore the relationship between wafer geometry and overlay error by the use of silicon test wafers with deliberate stress variations, i.e., engineered stress monitor (ESM) wafers. A process will be described that allows the creation of ESM wafers with nonuniform stress and includes many thousands of overlay targets for a detailed characterization of each wafer. Because the spatial character of the stress variation is easily changed, ESM wafers constitute a versatile platform for exploring nonuniform stress. We have fabricated ESM wafers of several different types, e.g., wafers where the center area has much higher stress than the outside area. Wafer geometry is measured with an optical metrology tool. After fabrication of the ESM wafers including alignment marks and first level overlay targets etched into the wafer, we expose a second level resist pattern designed to overlay with the etched targets. After resist patterning, relative overlay error is measured using standard optical methods. An innovative metric from the wafer geometry measurements is able to predict the process-induced overlay error. We conclude that appropriate wafer geometry measurements of in-process wafers have strong potential to characterize and reduce process-induced overlay errors.

Brunner, Timothy A.; Menon, Vinayan C.; Wong, Cheuk Wun; Gluschenkov, Oleg; Belyansky, Michael P.; Felix, Nelson M.; Ausschnitt, Christopher P.; Vukkadala, Pradeep; Veeraraghavan, Sathish; Sinha, Jaydeep K.

2013-10-01

381

Modeling Patterning of Heteroepitaxial Overlayers from Nano to Micron Scales  

NASA Astrophysics Data System (ADS)

Thin heteroepitaxial overlayers have been proposed as templates to generate stable, self-organized nanostructures at large length scales, with a variety of important technological applications. However, modeling strain-driven self-organization is a formidable challenge due to a large span of length and time scales involved. In this talk, I will present a method for predicting the patterning of ultrathin films on micron length scales with atomic resolution [K.R. Elder et al., Phys. Rev. Lett. 108, 226102 (2012)]. It is based on the Phase-Field Crystal model, which allows one to reach diffusive time scales for relaxation of the system. We make quantitative predictions for the type of superstructures (stripes, honeycomb, triangular) and length scales of pattern formation of both compressively strained and tensile overlayers on metal-metal systems, including Cu on Ru(0001), Cu on Pd(111), and Ag on Cu(111). Our findings are in excellent agreement with previous experiments and call for future experimental investigations of such systems.

Ala-Nissila, Tapio

2013-03-01

382

Using perspective guidance overlay to improve UAV manual control performance  

NASA Astrophysics Data System (ADS)

The guidance information that is available to the UAV operator typically suffers from limitations of data update rate and system latency. Even when using a flight director command display, the manual control task is considerably more difficult compared to piloting a manned aircraft. Results from earlier research into perspective guidance displays show that these displays provide performance benefits and suggest a reduction of the negative effects of system latency. The current study has shown that in case of limitations of data update rate and system latency the use of a conformal sensor overlay showing a perspective presentation of the trajectory constraints is consistently superior to the flight director command display. The superiority becomes more pronounced with an increase in data latency and a decrease in update rate. The fact that the perspective pathway overlay as used in this study can be implemented on any graphics system that is capable of rendering a set of 2-D vectors makes it a viable candidate for upgrades to current systems.

Tadema, Jochum; Theunissen, Eric; Koeners, Joris

2007-05-01

383

Coded multiple chirp spread spectrum system and overlay service  

NASA Technical Reports Server (NTRS)

An asynchronous spread-spectrum system called coded multiple chirp is proposed, and the possible spread-spectrum overlay over an analog FM-TV signal is investigated by computer simulation. Multiple single-sloped up and down chirps are encoded by a pseudonoise code and decoded by dechirpers (pulse-compression filters) followed by a digital code correlator. The performance of the proposed system, expressed in terms of in probability of bit error and code miss probability, is similar to that of FSK (frequency shift keying) using codewords if sufficient compression gain is used. When chirp is used to overlay an FM-TV channel, two chirp signals with data rate up to 25 kb/s could be overlaid in a 36-MHz satellite transponder without significant mutual interference. Performance estimates for a VSAT (very small aperture terminal) earth station operating at C-band show that a 2.4-m antenna and 300-mW transmitter could send a 2.4-kb/s signal to a large central earth station over an occupied channel.

Kim, Junghwan; Pratt, Timothy; Ha, Tri T.

1988-01-01

384

Lightweight storage and overlay networks for fault tolerance.  

SciTech Connect

The next generation of capability-class, massively parallel processing (MPP) systems is expected to have hundreds of thousands to millions of processors, In such environments, it is critical to have fault-tolerance mechanisms, including checkpoint/restart, that scale with the size of applications and the percentage of the system on which the applications execute. For application-driven, periodic checkpoint operations, the state-of-the-art does not provide a scalable solution. For example, on today's massive-scale systems that execute applications which consume most of the memory of the employed compute nodes, checkpoint operations generate I/O that consumes nearly 80% of the total I/O usage. Motivated by this observation, this project aims to improve I/O performance for application-directed checkpoints through the use of lightweight storage architectures and overlay networks. Lightweight storage provide direct access to underlying storage devices. Overlay networks provide caching and processing capabilities in the compute-node fabric. The combination has potential to signifcantly reduce I/O overhead for large-scale applications. This report describes our combined efforts to model and understand overheads for application-directed checkpoints, as well as implementation and performance analysis of a checkpoint service that uses available compute nodes as a network cache for checkpoint operations.

Oldfield, Ron A.

2010-01-01

385

An Analysis of LANDSAT4 Thematic Mapper Geometric Properties  

Microsoft Academic Search

Landsat-4 Thematic Mapper data of Washington, DC, Harrisburg, PA, and Salton Sea, CA were analyzed to determine geometric integrity and conformity of the data to known Earth surface geometry. Several tests were performed. Intraband correlation and interband registration were investigated. No problems were observed in the intraband analysis, and aside from indications of slight misregistration between bands of the primary

Richard E. Walker; Albert L. Zobrist; Nevin A. Bryant; Boris Gohkman; Steven Z. Friedman; Thomas L. Lpgan

1984-01-01

386

Monitoring Forest Succession Using Multitemporal Landsat Images: Factors of Uncertainties  

NASA Astrophysics Data System (ADS)

This study evaluates uncertainty factors in using multitemporal Landsat images for subtle change detection, including atmosphere, topography, phenology, sun and view angles. The study is based on monitoring forest succession with a set of multiple Landsat TM/ETM+ images spanning 15 years over the H. J. Andrews Experimental Forest in the Western Cascades of Oregon. The algorithms for removing atmospheric effects from remotely sensed images evaluated include a new version of dark object subtraction (DOS3) method, the dense dark vegetation (DDV) method, the path radiance (PARA) approach, and the 6S radiative transfer codes. We found that the DOS3 approach under-corrects the image, and the recently developed DDV and PARA approaches can produce surface reflectance values closely matching those produced by 6S using in situ measurements of atmospheric aerosol optical depth. Atmospheric effects reduce NDVI and Greenness, and increase Brightness and Wetness. Topography modifies Brightness and Greenness, but has minimal effects on NDVI and Wetness, and it interacts with sun angle. Forest stands at late successional stages are more sensitive to topography than younger stands. Though the study areas are covered predominantly by evergreen needle leaf forests, phenological effect is significant. Sun angle effects are confounded with phenology, and reflectance values for stands at different successional stages are related to sun angles nonlinearly. Though Landsat has a small field of view angle, the view angle effects from overlapping Landsat scenes for a mountainous forested landscape may not be ignored when monitoring forest succession with multitemporal images.

Song, C.

2004-05-01

387

LEDAPS: A North American Disturbance Record from Landsat Imagery  

NASA Astrophysics Data System (ADS)

The disturbance regime of forests exerts a strong control on North American terrestrial carbon dynamics. Disturbance events themselves (fire, harvest, insect damage) emit carbon directly to the atmosphere; regrowth following disturbance tends to sequester carbon from the atmosphere. In general, the spatio-temporal patterns of disturbance control the age structure and successional patterns of forests, and thus influence net ecosystem productivity on a regional basis. The Landsat remote sensing program has collected high-resolution (30-80 meter resolution) imagery since 1972, and provides an excellent tool for assessing recent disturbance patterns. To date, however, this archive has not been comprehensively analyzed for such information. To remedy this, the LEDAPS (Landsat Ecosystem Disturbance Adaptive Processing System) project at NASA GSFC is processing decadal Landsat imagery centered on 1975, 1990, and 2000 epochs to map forest disturbance rates and patterns across North America. Landsat imagery is calibrated and atmospherically corrected to surface reflectance using the 6S radiative transfer model. Disturbance patterns are extracted in two phases. First, a simple Disturbance Index (S. Healey, personal communication) is used to map the location of significant biomass loss following a `tasseled cap' radiometric transformation. Second, we are experimenting with the integration of canopy reflectance models to relate pixel radiometry directly to stand attributes (canopy cover, forest type) to better characterize regrowth state. Initial "Beta" products have been released and feedback from the land science community is invited. This presentation will give an overview of the LEDAPS project, and present initial results from reflectance processing and disturbance mapping.

Masek, J. G.; Hall, F.; Wolfe, R.; Cohen, W.

2004-12-01

388

Spot: How Good for Geology: A Comparison with Landsat MSS.  

National Technical Information Service (NTIS)

Geological interpretation possibilities of SPOT MSS and LANDSAT MSS positive prints enlarged to the same scale were compared, using as a test area part of the Jebel Amour (Algeria). The SPOT imagery offers many advantages, filling the gap between remote s...

A. Sesoeren

1986-01-01

389

Educator's Guide for Mission to Earth: LANDSAT Views the World  

NASA Technical Reports Server (NTRS)

This teacher's guide is specifically designed to provide information and suggestions for using LANDSAT imagery to teach basic concepts in several content areas. Content areas include: (1) Earth science and geology; (2) environmental studies; (3) geography; and (4) social and urban studies.

Tindal, M. A.

1978-01-01

390

The Delaware River basin LANDSAT-data collection system experiment  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. This experiment successfully demonstrated that standard U.S. Geological Survey field instrumentation could be easily interfaced with the LANDSAT-DCS and the data made to flow smoothly to water resources management agencies. The experiment was conducted in the Delaware River basin. A truly operational system could not be deployed.

Paulson, R. W. (principal investigator)

1975-01-01

391

Simulation of meteorological satellite (METSAT) data using LANDSAT data  

NASA Technical Reports Server (NTRS)

The information content which can be expected from the advanced very high resolution radiometer system, AVHRR, on the NOAA-6 satellite was assessed, and systematic techniques of data interpretation for use with meteorological satellite data were defined. In-house data from LANDSAT 2 and 3 were used to simulate the spatial, spectral, and sampling methods of the NOAA-6 satellite data.

Austin, W. W.; Ryland, W. E.

1983-01-01

392

Use of LANDSAT Imagery for Geological and Hydrological Mapping.  

National Technical Information Service (NTIS)

In this work, examples of different application of Landsat imagery are displayed, for different themes. Work is done in a visual form, using for that the conventional methodology of photo-interpretation. The object of the present work is to choose the for...

J. Ulibarrena A. Rojo C. Schoeder

1982-01-01

393

Spectral characterization of the LANDSAT-D multispectral scanner subsystems  

NASA Technical Reports Server (NTRS)

Relative spectral response data for the multispectral scanner subsystems (MSS) to be flown on LANDSAT-D and LANDSAT-D backup, the protoflight and flight models, respectively, are presented and compared to similar data for the Landsat 1,2, and 3 subsystems. Channel-bychannel (six channels per band) outputs for soil and soybean targets were simulated and compared within each band and between scanners. The two LANDSAT-D scanners proved to be nearly identical in mean spectral response, but they exhibited some differences from the previous MSS's. Principal differences between the spectral responses of the D-scanners and previous scanners were: (1) a mean upper-band edge in the green band of 606 nm compared to previous means of 593 to 598 nm; (2) an average upper-band edge of 697 nm in the red band compared to previous averages of 701 to 710 nm; and (3) an average bandpass for the first near-IR band of 702-814 nm compared to a range of 693-793 to 697-802 nm for previous scanners. These differences caused the simulated D-scanner outputs to be 3 to 10 percent lower in the red band and 3 to 11 percent higher in the first near-IR band than previous scanners for the soybeans target. Otherwise, outputs from soil and soybean targets were only slightly affected. The D-scanners were generally more uniform from channel to channel within bands than previous scanners.

Markham, B. L. (principal investigator); Barker, J. L.

1982-01-01

394

Estimating time since forest harvest using segmented Landsat ETM+ imagery  

Microsoft Academic Search

Modeling of forest carbon (C) dynamics requires precise information regarding when a disturbance occurred and the age of regeneration present. Generally, this information is obtained in the age class attribute of forest inventories; however forest inventories can become quickly outdated when disturbance events are not continuously integrated into the database. In this study, Landsat ETM+ image data and Tasseled Cap

M. A. Wulder; R. S. Skakun; W. A. Kurz; J. C. White

2004-01-01

395

LANDSAT menhaden and thread herring resources investigation, Gulf of Mexico  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. The most significant achievement thus far includes the successful charting of high probability fishing areas from LANDSAT MSS data and the successful simulation of an operational satellite system to provide tactical information for the commercial harvest of menhaden.

Savastano, K. (principal investigator); Kemmerer, A. J.; Leming, T.; Holley, H.; Faller, K. H.

1977-01-01

396

Multispectral data restoration study. [digital correction of LANDSAT geographic data  

NASA Technical Reports Server (NTRS)

A digital resampling technique for LANDSAT data is reported that incorporates a deconvolution concept to minimize spatial and radiometric degradation of data during resampling for geometric correction. A quantitative comparison of cubic convolution and digital restoration methods establishes the latter as the superior technique.

Shah, N. J.; Wilson, C. L.

1977-01-01

397

Landsat 8 on-orbit characterization and calibration system  

NASA Astrophysics Data System (ADS)

The Landsat Data Continuity Mission (LDCM) is planning to launch the Landsat 8 satellite in December 2012, which continues an uninterrupted record of consistently calibrated globally acquired multispectral images of the Earth started in 1972. The satellite will carry two imaging sensors: the Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS). The OLI will provide visible, near-infrared and short-wave infrared data in nine spectral bands while the TIRS will acquire thermal infrared data in two bands. Both sensors have a pushbroom design and consequently, each has a large number of detectors to be characterized. Image and calibration data downlinked from the satellite will be processed by the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center using the Landsat 8 Image Assessment System (IAS), a component of the Ground System. In addition to extracting statistics from all Earth images acquired, the IAS will process and trend results from analysis of special calibration acquisitions, such as solar diffuser, lunar, shutter, night, lamp and blackbody data, and preselected calibration sites. The trended data will be systematically processed and analyzed, and calibration and characterization parameters will be updated using both automatic and customized manual tools. This paper describes the analysis tools and the system developed to monitor and characterize on-orbit performance and calibrate the Landsat 8 sensors and image data products.

Micijevic, Esad; Morfitt, Ron; Choate, Michael

2011-09-01

398

Design study for LANDSAT D attitude control system  

NASA Technical Reports Server (NTRS)

A design and performance evaluation is presented for the LANDSAT D attitude control system (ACS). Control and configuration of the gimballed Ku-band antenna system for communication with the tracking and data relay satellite (TDRS). Control of the solar array drive considered part of the ACS is also addressed.

Iwens, R. P.; Bernier, G. E.; Hofstadter, R. F.

1976-01-01

399

Landsat maps of Iraq: tools for non-invasive exploration  

SciTech Connect

Optical analysis of Landsat imagery is a valuable preliminary step for exploration in areas where a detailed geologic base is lacking, logistics are difficult, or the political situation is insecure. Two maps of Iraq produced by such analysis elucidate structural and lithologic relations across a broad oil-producing region. The Landsat map of Iraq is divided into units based on drainage patterns, surface textures, relative resistance to erosion, and color. These units tentatively correlate to the broadly generalized geologic map of Iraq. The Landsat map clearly delineates Iraq's 3 major geotectonic zones: desert and alluvial plains, simply folded, and overthrust. The Lineament and anomaly map, derived from optically enhanced imagery, shows noncultural lineaments and 5 types of anomalies: linear, circular, structural, textural, and shade. Conjugate shear sets from lineaments oblique to the regional and local compression directions. Lineaments also reflect normal faults, tear faults, thrust fronts, structural control of wadis, and wind-direction features. The intersection of 3 or more lineaments defines a linear anomaly. Circular anomalies can be attributed to structural domes or basins, diapirs, calderas, or astroblemes. Appreciable deviations from local deformational style are considered structural anomalies. Textural anomalies are abrupt changes in texture unrelated to lithologic changes. Shade anomalies, mapped from band 5 enhancements, reflect a shade change from light to dark, usually across a lineament. Comparison of oil field locations to Landsat-mapped units, lineaments, and anomalies can indicate exploration targets for more detailed ground-based geologic and seismic investigation.

Gawarecki, S.L.; Perry, S.K.

1984-04-01

400

Investigation of several aspects of LANDSAT-4 data quality  

NASA Technical Reports Server (NTRS)

No insurmountable problems in change detection analysis were found when portions of scenes collected simultaneously by LANDSAT 4 MSS and either LANDSAT 2 or 3. The cause of the periodic noise in LANDSAT 4 MSS images which had a RMS value of approximately 2DN should be corrected in the LANDSAT D instrument before its launch. Analysis of the P-tape of the Arkansas scene shows bands within the same focal plane very well registered except for the thermal band which was misregistered by approximately three 28.5 meter pixels in both directions. It is possible to derive tight confidence bounds for the registration errors. Preliminary analyses of the Sacramento and Arkansas scenes reveals a very high degree of consistency with earlier results for bands 3 vs 1, 3 vs 4, and 3 vs 5. Results are presented in table form. It is suggested that attention be given to the standard deviations of registrations errors to judge whether or not they will be within specification once any known mean registration errors are corrected. Techniques used for MTF analysis of a Washington scene produced noisy results.

Wrigley, R. C. (principal investigator)

1983-01-01

401

Waterline extraction from Landsat TM data in a tidal flat  

Microsoft Academic Search

Waterline extraction is potentially one of the most effective satellite remote sensing tools for studying changes in tidal flat environment and coastlines. However, its application to the study of tidal flats has not been investigated in detail. The waterline in a tidal flat in Gomso Bay, Korea is characterized and evaluated using 27 sets of Landsat thematic mapper (TM) and

Joo-Hyung Ryu; Joong-Sun Won; Kyung Duck Min

2002-01-01

402

LANDSAT-D flight segment operations manual, volume 2  

NASA Technical Reports Server (NTRS)

Functions, performance capabilities, modes of operation, constraints, redundancy, commands, and telemetry are described for the thematic mapper; the global positioning system; the direct access S-band; the multispectral scanner; the payload correction; the thermal control subsystem; the solar array retention, deployment, and jettison assembly; and the boom antenna retention, deployment, and jettison assembly for LANDSAT 4.

Varhola, J.

1981-01-01

403

Geometric accuracy of LANDSAT-4 MSS image data  

NASA Technical Reports Server (NTRS)

Analyses of the LANDSAT-4 MSS image data of North Georgia provided by the EDC in CCT-p formats reveal that errors of approximately + or - 30 m in the raw data can be reduced to about + or - 55 m based on rectification procedures involving the use of 20 to 30 well-distributed GCPs and 2nd or 3rd degree polynomial equations. Higher order polynomials do not appear to improve the rectification accuracy. A subscene area of 256 x 256 pixels was rectified with a 1st degree polynomial to yield an RMSE sub xy value of + or - 40 m, indicating that USGS 1:24,000 scale quadrangle-sized areas of LANDSAT-4 data can be fitted to a map base with relatively few control points and simple equations. The errors in the rectification process are caused by the spatial resolution of the MSS data, by errors in the maps and GCP digitizing process, and by displacements caused by terrain relief. Overall, due to the improved pointing and attitude control of the spacecraft, the geometric quality of the LANDSAT-4 MSS data appears much improved over that of LANDSATS -1, -2 and -3.

Welch, R.; Usery, E. L.

1983-01-01

404

Construction of New Area Sampling Frames Using Landsat Imagery.  

National Technical Information Service (NTIS)

The U.S. Department of Agriculture develops Area Sampling Frames (ASF's) for each state using a series of land-use maps, and utilizes them is selecting statistical samples for agricultural surveys. Recently, Landsat imagery provided up-to-date land-use in...

D. J. Costanzo

1983-01-01

405

Exploitation of Landsat imagery and ancillary data for battlespace characterization  

Microsoft Academic Search

Spectral data provide opportunities to discriminate targets from background clutter and to detect partially concealed objects. However, data with high spatial resolution generally are not synoptic scale (hundreds of kilometers). By analyzing courser resolution synoptic imagery, high-resolution sensors can then be cued to areas of potential targets. Multispectral images (Landsat 7) are combined with ancillary data-lines of communication, digital elevation

Seth M. Orloff; Su May Hsu; H.-H. K. Burke

2002-01-01

406

Implementation of LANDSAT technology in the Commonwealth of Virginia  

NASA Technical Reports Server (NTRS)

A brief history of events which led to the formal implementation of LANDSAT technology in Virginia is outlined. The concept of the Commonwealth Data Base (CDB) is explained as it is perceived by the users and the systems development task force. Furthermore, the CDB organization which was established to implement the CDB concept in Virginia is covered.

Sahaydak, E.

1981-01-01

407

DO EXOTIC CURRENCIES IMPROVE THE RISK-ADJUSTED PERFORMANCE OF DYNAMIC CURRENCY OVERLAYS?  

Microsoft Academic Search

This paper investigates the benefits of additional international diversification into emerging stock markets, from the point of view of a U.S investor. The increase in risk adjusted returns with exotic currencies (compared to a benchmark portfolio of only major currencies investments) is achieved through the use of a currency overlay programme. We assess the impact of the exotic currency overlay

Christian L. Dunis; Natan Levy

2001-01-01

408

Cracking resistance of thin-bonded overlays using fracture test, numerical simulations and early field performance  

Microsoft Academic Search

Thin-bonded bituminous overlays are becoming an increasingly popular pavement maintenance treatment, which can be used to restore smoothness, seal and renew the pavement surface and increase skid resistance. Thin-bonded overlays (TBOs) are constructed using a specialised type of paving equipment called a ‘spray paver’. A spray paver combines the operation of applying a tack coat and laying down asphalt concrete

Sarfraz Ahmed; Eshan V. Dave; William G. Buttlar; Marvin K. Exline

2012-01-01

409

Concrete Bridge Deck Overlays in Illinois: Mix Design Experimentation and Investigation of Construction Methods.  

National Technical Information Service (NTIS)

The purpose of a bridge deck overlay is to extend the life of a structure by providing a durable wearing surface and a barrier against chloride intrusion. The majority of the deck overlays in Illinois' recent past have contained microsilica. Problems asso...

B. A. Pfeifer

1999-01-01

410

Dynamic Topology Configuration in Service Overlay Networks: A Study of Reconfiguration Policies  

Microsoft Academic Search

The routing infrastructure of the Internet has be- come resistant to fundamental changes and the use of overlay networks has been proposed to provide additional flexibility and control. One of the most prominent configurable components of an overlay network is its topology, which can be dynami- cally reconfigured to accommodate communication requirements that vary over time. In this paper, we

Jinliang Fan; Mostafa H. Ammar

2006-01-01

411

Solid\\/liquid erosion behavior of gas tungsten arc welded TiNi overlay  

Microsoft Academic Search

The gas tungsten arc welding (GTAW) process has been widely used in the surface damage reparation of industrial and hydraulic handling components to yield a hardfacing overlay typically composed of nickel based alloys. The pseudoelasticity of TiNi intermetallic alloy provides excellent fatigue resistance and cavitation erosion resistance. GTAW was chosen to yield a TiNi alloy overlay onto AISI 1048 medium

J. R Weng; J. T Chang; K. C Chen; J. L He

2003-01-01

412

Weld overlay coatings for erosion control. Task A: Literature review, progress report  

Microsoft Academic Search

A literature review was made. In spite of similarities between abrasive wear and solid particle erosion, weld overlay hardfacing alloys that exhibit high abrasion resistance may not necessarily have good erosion resistance. The performance of weld overlay hardfacing alloys in erosive environments has not been studied in detail. It is believed that primary-solidified hard phases such as carbides and intermetallic

B. Levin; J. N. DuPont; A. R. Marder

1993-01-01

413

The effect of overlay stress on the uniaxial anisotropy of garnet bubble domain films  

Microsoft Academic Search

In the overlay films used for bubble domain propagation circuitry elastic energy is stored. Some of this energy is transferred to the LPE garnet film and because of the magnetoelastic coupling, significant alterations can be caused in the uniaxial anisotropy, Ku. The amount of elastic energy stored in the overlay is typically proportional to the product of the film stress

E. Klokholm; R. Anderson

1976-01-01

414

A new approach for overlay text detection and extraction from complex video scene.  

PubMed

Overlay text brings important semantic clues in video content analysis such as video information retrieval and summarization, since the content of the scene or the editor's intention can be well represented by using inserted text. Most of the previous approaches to extracting overlay text from videos are based on low-level features, such as edge, color, and texture information. However, existing methods experience difficulties in handling texts with various contrasts or inserted in a complex background. In this paper, we propose a novel framework to detect and extract the overlay text from the video scene. Based on our observation that there exist transient colors between inserted text and its adjacent background, a transition map is first generated. Then candidate regions are extracted by a reshaping method and the overlay text regions are determined based on the occurrence of overlay text in each candidate. The detected overlay text regions are localized accurately using the projection of overlay text pixels in the transition map and the text extraction is finally conducted. The proposed method is robust to different character size, position, contrast, and color. It is also language independent. Overlay text region update between frames is also employed to reduce the processing time. Experiments are performed on diverse videos to confirm the efficiency of the proposed method. PMID:19095537

Kim, Wonjun; Kim, Changick

2009-02-01

415

Improving Chinese Internet's Resilience through Degree Rank Based Overlay Relays Placement  

Microsoft Academic Search

The current interdomain routing protocol (BGP) used in the Internet tends to be restrictive limiting communication between source-destination pairs to one route, which may not fully utilize the potential Internet's connection redundancy. Although overlay routing could utilize redundant communication paths between endpoints to improve reliability and performance of the Internet, the studies of overlay network still suffer two handicaps: (i)

Bin Yuan; Guoqiang Zhang; Yanjun Li; Guoqing Zhang; Zhongcheng Li

2008-01-01

416

Nyiragongo volcano, Congo, Pre-eruption Perspective View, SRTM / Landsat  

NASA Technical Reports Server (NTRS)

The Nyiragongo volcano in the Congo erupted on January 17, 2002, and subsequently sent streams of lava into the city of Goma on the north shore of Lake Kivu. More than 100 people were killed, more than 12000 homes were destroyed, and hundreds of thousands were forced to flee the broader community of nearly half a million people. This computer generated visualization combines a Landsat satellite image and an elevation model from the Shuttle Radar Topography Mission (SRTM) to provide a view of both the volcano and the city of Goma, looking slightly east of north.

Nyiragongo is the steep volcano on the right, Lake Kivu is in the foreground, and the city of Goma has a light pink speckled appearance along the shoreline. Nyiragongo peaks at about 3470 meters (11,380 feet) elevation and reaches almost exactly 2000 meters (6560 feet) above Lake Kivu. The shorter but broader Nyamuragira volcano appears in the left background. Topographic expression has been exaggerated vertically by a factor of 1.5 for this visualization.

Goma, Lake Kivu, Nyiragongo, Nyamuragira and other nearby volcanoes sit within the East African Rift Valley, a zone where tectonic processes are cracking, stretching, and lowering the Earth's crust. Volcanic activity is common here, and older but geologically recent lava flows (magenta in this depiction) are particularly apparent on the flanks of the Nyamuragira volcano.

The Landsat image used here was acquired on December 11, 2001, about a month before the eruption, and shows an unusually cloud-free view of this tropical terrain. Minor clouds and their shadows were digitally removed to clarify the view, topographic shading derived from the SRTM elevation model was added to the Landsat image, and a false sky was added.

Landsat has been providing visible and infrared views of the Earth since 1972. SRTM elevation data matches the 30-meter (98-foot) resolution of most Landsat images and substantially helps in analyzing the large and growing Landsat image archive. This Landsat 7 Thematic Mapper image was provided to the SRTM project by the United States Geological Survey, Earth Resources Observation Systems (EROS) Data Center, Sioux Falls, S.D.

Elevation data used in this image was acquired by the Shuttle Radar Topography Mission (SRTM) aboard the Space Shuttle Endeavour, launched on Feb. 11, 2000. SRTM used the same radar instrument that comprised the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) that flew twice on the Space Shuttle Endeavour in 1994. SRTM was designed to collect 3-D measurements of the Earth's surface. To collect the 3-D data, engineers added a 60-meter (approximately 200-foot) mast, installed additional C-band and X-band antennas, and improved tracking and navigation devices. The mission is a cooperative project between NASA, the National Imagery and Mapping Agency (NIMA) of the U.S. Department of Defense and the German and Italian space agencies. It is managed by NASA's Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Earth Science Enterprise, Washington, D.C.

Size: View width 21 kilometers (13 miles), View distance 42 kilometers (26 miles) Location: 1.5 deg. South lat., 29.3 deg. East lon. Orientation: View east-northeast, 5 degrees below horizontal Image Data: Landsat Bands 3, 2, 1 as red, green, blue, respectively. Original Data Resolution: SRTM 1 arcsecond (30 meters or 98 feet), Landsat 30 meters (98 feet) Date Acquired: February 2000 (SRTM), 11 December 2001 (Landsat)

2002-01-01

417

Integrated production overlay field-by-field control for leading edge technology nodes  

NASA Astrophysics Data System (ADS)

As photolithography will continue with 193nm immersion multiple patterning technologies for the leading edge HVM process node, the production overlay requirement for critical layers in logic devices has almost reached the scanner hardware performance limit. To meet the extreme overlay requirements in HVM production environment, this study investigates a new integrated overlay control concept for leading edge technology nodes that combines the run-to-run (R2R) linear or high order control loop, the periodic field-by-field or correction per exposure (CPE) wafer process signature control loop, and the scanner baseline control loop into a single integrated overlay control path through the fab host APC system. The goal is to meet the fab requirements for overlay performance, lower the cost of ownership, and provide freedom of control methodology. In this paper, a detailed implementation of this concept will be discussed, along with some preliminary results.

Chung, Woong Jae; Tristan, John; Gutjahr, Karsten; Subramany, Lokesh; Li, Chen; Sun, Yulei; Yelverton, Mark; Kim, Young Ki; Kim, Jeong Soo; Huang, Chin-Chou Kevin; Pierson, William; Karur-Shanmugam, Ramkumar; Riggs, Brent; Jug, Sven; Robinson, John C.; Yap, Lipkong; Ramanathan, Vidya

2014-04-01

418

Innovative techniques for improving overlay accuracy by using DCM (device correlated metrology) targets as reference  

NASA Astrophysics Data System (ADS)

Overlay metrology performance as Total Measurement Uncertainty (TMU), design rule compatibility, device correlation and measurement accuracy are been challenged at 2x nm node and below. Process impact on overlay metrology becoming critical, and techniques to improve measurement accuracy becomes increasingly important. In this paper, we present an innovative methodology for improving overlay accuracy. A propriety quality metric, Qmerit, is used to identify overlay metrology measurement settings with least process impacts and reliable accuracies. Using the quality metric, an innovative calibration method, ASC (Archer Self Calibration) is then used to remove the inaccuracies. Accuracy validation can be achieved by correlation to reference overlay data from another independent metrology source such as CDSEM data collected on DCM (Device Correlated Metrology) hybrid target or electrical testing. Additionally, reference metrology can also be used to verify which measurement conditions are the most accurate. In this paper we bring an example of such use case.

Tzai, Wei-Jhe; Hsu, Simon C. C.; Chen, Howard; Chen, Charlie; Pai, Yuan Chi; Yu, Chun-Chi; Lin, Chia Ching; Itzkovich, Tal; Yap, Lipkong; Amit, Eran; Tien, David; Huang, Eros; Kuo, Kelly T. L.; Amir, Nuriel

2014-04-01

419

Mapping forest succesion types in Siberia with Landsat data  

NASA Astrophysics Data System (ADS)

We develop a forest typology system based on dynamic vegetation approach and apply it to the analysis of the forest type distribution for several test areas in Siberia, aiming at capability of mapping whole Siberian forests based on Landsat data. Test region locations are: two in West Siberian middle taiga (Laryegan and Nyagan), one in Central Siberia and one in East Siberia near Yakutsk. The ground truth data are based on analysis of the field survey, forest inventory data from the point of view of the successional forest type classification. Supervised classification was applied to the areas covered with analysis of the ground truth and inventory data, using several limited area maps and vegetation survey transects published in literature. In Laryegan basin the upland forest areas are dominated (as climax forest species) by Scots pine on sandy soils and Siberian pine with presence of fir and spruce on the others. Those types are separable using Landsat spectral data alone. In the permafrost area around Yakutsk the most widespread succession type is birch to larch succession. Three stages of the birch to larch succession are detectable from Landsat image. When Landsat data is used in both West and East Siberia, distinction between deciduous broad-leaved species (birch, aspen, and willow) is difficult due to similarity in spectral signatures. Same problem exist for distinguishing between dark coniferous species (Siberian pine, fir and spruce). Image classification can be improved by applying landscape type analysis, such as separation into floodplain, terrace, sloping hills. Additional layers of information seem to be a promising way to complement Landsat data, including SAR-based biomass maps and terrain data

Maksyutov, S. S.; Sedykh, V.; Kleptsova, I.; Frolov, A.; Silaev, A.; Kuzmenko, E.; Farber, S.; Kuzmik, N.; Sokolov, V. A.; Fedorov, A.; Nikolaeva, S.

2013-12-01

420

Suppression des Aerosols sur l'Imagerie Landsat Thematic Mapper (Suppression of Aerosols on Landsat Thematic Mapper Imagery).  

National Technical Information Service (NTIS)

A numerical count (DN) correction was carried out in each spectral band of LANDSAT Thematic Mapper after estimating the abundance of aerosols covering each pixel by the 4th parameter of the tasseled cap transformations. The corrected DN is calculated usin...

J. Lavreau

1991-01-01

421

Lipid adlayer organization mediated by a liquid overlayer.  

PubMed

We report on the formation of a chemically bound 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) monolayer on modified Au and silica surfaces, and changes in the organization of the interfacial lipid layer associated with immersion in aqueous solution. We have studied the interface using steady state and time resolved fluorescence spectroscopy, water contact angle and optical ellipsometry measurements, and electrochemical methods. Our data reveal that the DMPC adlayer in contact with air forms a relatively well organized interface that mediates the rotational motion of perylene. In the presence of an aqueous overlayer, perylene reorientation becomes more rapid, consistent with a reduction in the organization of the interfacial lipid adlayer. One implication of this finding is that the interfacial adlayer is less than a uniform monolayer, which is confirmed by electrochemical data. Our data underscore the importance of water in mediating the organization of interfacial lipid adlayers. PMID:22995467

Baumler, S M; Blanchard, G J

2012-12-01

422

Pressure reduction with a hospitalized population using a mattress overlay.  

PubMed

Billions of dollars are spent each year on treating pressure ulcers. With healthcare costs climbing and reform the order of the day, it is essential for researchers to identify a device which reduces pressure, is easy to use and is cost effective. This study used a Mini-Tipe pressure sensor to measure pressure readings over the sacral and trochanter areas of 17 subjects identified as being at risk for skin breakdown. Pressures were compared on a standard hospital mattress and an anatomically contoured mattress overlay. There was a 48 percent reduction in mean pressures over the sacral area and a 23 percent reduction over the trochanter. No correlations between pressures and demographic data were identified. Further research is warranted to determine the effects of variables found in an "at risk" population on pressure reduction with various products. PMID:7779234

Suarez, C H; Reynolds, A

1995-01-01

423

AFM dissipation topography of soliton superstructures in adsorbed overlayers  

NASA Astrophysics Data System (ADS)

In the atomic force microscope, the nanoscale force topography of even complex surface superstructures is extracted by the changing vibration frequency of a scanning tip. An alternative dissipation topography with similar or even better contrast has been demonstrated recently by mapping the (x,y) -dependent tip damping but the detailed damping mechanism is still unknown. Here we identify two different tip dissipation mechanisms: local mechanical softness and hysteresis. Motivated by recent data, we describe both of them in a one-dimensional model of Moiré superstructures of incommensurate overlayers. Local softness at “soliton” defects yields a dissipation contrast that can be much larger than the corresponding density or corrugation contrast. At realistically low vibration frequencies, however, a much stronger and more effective dissipation is caused by the tip-induced nonlinear jumping of the soliton, naturally developing bistability and hysteresis. Signatures of this mechanism are proposed for experimental identification.

Negri, Carlotta; Manini, Nicola; Vanossi, Andrea; Santoro, Giuseppe E.; Tosatti, Erio

2010-01-01

424

Fusion of Landsat with MODIS imagery to produce vegetation and change information with Landsat spatial and MODIS temporal characteristics  

NASA Astrophysics Data System (ADS)

Landsat imagery with a 30 m spatial resolution has advantageous spatial and spectral characteristics for describing landscape-level biodiversity and vegetation cover. The sensor's revisit rate or temporal resolution of 16 days, however, limits its ability to characterize vegetation dynamics, especially when considering that cloud cover may lengthen this interval considerably, particularly at higher latitudes with shorter growing seasons. For instance, the probability of acquiring a cloud-free Landsat scene can be as low as 10% for some regions in Canada, often even precluding acquisition of annual imagery. In contrast, the MODerate- resolution Imaging Spectroradiometer (MODIS) has a high temporal resolution, orbiting the Earth once per day, and depending on the spectral characteristics of interest, the data has spatial resolutions of 250 m, 500 m, and 1000 m. By combining Landsat and MODIS data, we are able to capitalize on the spatial detail of Landsat and the temporal regularity of MODIS acquisitions. In this study, we develop a new data fusion approach to detect changes in vegetation conditions and cover at a 30 m resolution and 8-day time intervals. Landsat imagery is used to detect and identify spatial changes based on Tasseled Cap transformed vegetation brightness, wetness, and greenness. Eight-day MODIS composites are then used to determine the time interval at which these changes occurred and a synthetic change mask is generated. The algorithm is tested over a 38,300 km2 study site in southern Alberta, Canada, and verified using vector based disturbance data recorded between 2000 and 2005. Changes in vegetation cover were found to be accurately described and the approach helped minimizing the technical limitations associated with high spatial and temporal resolution data requirements.

Hilker, T.; Coops, N. C.; Wulder, M. A.; McDermid, G.; White, J. C.

2008-12-01

425

Effect of etch pattern transfer on local overlay (OVL) margin in 28nm gate integration.  

NASA Astrophysics Data System (ADS)

One of the main process control challenges in logic process integration is the contact to gate overlay. Usual ways for overlay control are run to run corrections (high order process corrections) and scanner control (baseliner control loop) to keep overlay within the very tight ITRS specifications, i.e. 7nm mean+3sigma. It is known that process integration can lead to specific overlay distortion (CMP, thermal treatment etc…) which are usually partly handled by high order process corrections at scanner level. In addition, recently we have shown that etch process can also lead to local overlay distortions, especially at the wafer edge [1]. In this paper we look into another overlay distortion level which can happen during etch processes. We will show that resist cure steps during gate patterning affect lithography defined profiles leading to local pattern shifting. This so called gate shifting has been characterized by etch process partitioning during a typical high-K metal gate patterning with spinon carbon and Si-ARC lithography stack onto a high-K metal gate / poly-silicon / oxide hard mask stack. We will show that modifying the resist-cure / Si-ARC open chemistry strongly contributes to gate shifting reduction by an equivalent of 40% overlay margin reduction.

Ros, Onintza; Gouraud, Pascal; Le-Gratiet, Ber