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Larsen Ice Shelf
This sub-image of the Antarc
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2/20/01
| Date |
2/20/01 |
| Description |
This sub-image of the Antarctic Peninsula from the 2000 Antarctic Mapping Mission focuses on the northern end of the Larsen Ice Shelf. The blue line shows the coastline in 1997, the red line in 1992, based on synthetic aperture radar imagery from the European Space Agency, and the yellow line in the mid-1970s. The northern Larsen has been retreating since the 1960s, with major collapses in the 1990s. The southern Larsen was advancing until a major collapse in 1995. Small areas, however, also show advancement since 1997, including a section near the Sobral Peninsula in the center of the image. These advancements may indicate early rebuilding of the overall extent of the Larsen Shelf. The two RADARSAT mosaics from 1997 and 2000 Antarctic imaging campaigns provide highly accurate snapshots of this rapidly changing region of the greater Antarctic continent. The Antarctic Mapping Mission is a joint project between NASA and the Canadian Space Agency. The project is led by Ohio State University in Columbus in partnership with the Alaska Synthetic Aperture Radar (SAR) Facility at the University of Alaska Fairbanks, NASA's Jet Propulsion Laboratory, Pasadena, Calif., and the Vexcel Corporation, Boulder, Colo. The Canadian Space Agency's RADARSAT-1 satellite carries a synthetic aperture radar, an imaging radar sensor that operates at C-band (5.3 GHz frequency) with horizontal transmit-horizontal receive polarization from an orbital altitude of about 800 kilometers (500 miles). The 1997 Antarctic Mapping Mission took place between Sept. 19 and Oct. 14 and mapped the entire Antarctic continent. The 2000 Antarctic Mapping Mission lasted from Sept. 3 to Nov. 4 and obtained complete coverage of Antarctica north of 82 degrees south latitude. Photo Credit: Canadian Space Agency/NASA/Ohio State University, Jet Propulsion Laboratory, Alaska SAR Facility # # # # # |
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Silk Route, China C, L bands
This composite image is of a
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9/29/94
| Date |
9/29/94 |
| Description |
This composite image is of an area thought to contain the ruins of the ancient settlement of Niya. It is located in the southwest corner of the Taklamakan Desert in China's Sinjiang Province. This region was part of some of China's earliest dynasties and from the third century BC on was traversed by the famous Silk Road. The Silk Road, passing east-west through this image, was an ancient trade route that led across Central Asia's desert to Persia, Byzantium and Rome. The multi-frequency, multi-polarized radar imagery was acquired on orbit 106 of the space shuttle Endeavour on April 16, 1994 by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar. The image is centered at 37.78 degrees north latitude and 82.41 degrees east longitude. The area shown is approximately 35 kilometers by 83 kilometers (22 miles by 51 miles). The image is a composite of an image from an Earth-orbiting satellite called Systeme Probatoire d'Observation de la Terre (SPOT) and a SIR-C multi- frequency, multi-polarized radar image. The false-color radar image was created by displaying the C-band (horizontally transmitted and received) return in red, the L-band (horizontally transmitted and received) return in green, and the L-band (horizontally transmitted and vertically received) return in blue. The prominent east/west pink formation at the bottom of the image is most likely a ridge of loosely consolidated sedimentary rock. The Niya River -- the black feature in the lower right of the French satellite image -- meanders north- northeast until it clears the sedimentary ridge, at which point it abruptly turns northwest. Sediment and evaporite deposits left by the river over millennia dominate the center and upper right of the radar image (in light pink). High ground, ridges and dunes are seen among the riverbed meanderings as mottled blue. Through image enhancement and analysis, a new feature probably representing a man-made canal has been discovered and mapped. ----- Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) is part of NASA's Mission to Planet Earth. The radars illuminate Earth with microwaves, allowing detailed observations at any time, regardless of weather or sunlight conditions. SIR-C/X-SAR uses three microwave wavelengths: the L- band (24 cm), C-band (6 cm) and X-band (3 cm). The multi- frequency data will be used by the international scientific community to better understand the global environment and how it is changing. The SIR-C/X-SAR data, complemented by aircraft and ground studies, will give scientists clearer insights into those environmental changes which are caused by nature and those changes which are induced by human activity. SIR-C was developed by NASA's Jet Propulsion Laboratory. X-SAR was developed by the Dornier and Alenia Spazio companies for the German space agency, Deutsche Agentur fuer Raumfahrtangelegenheiten (DARA), and the Italian space agency, Agenzia Spaziale Italiana (ASI), with the Deutsche Forschungsanstalt fuer Luft und Raumfahrt e.v.(DLR), the major partner in science, operations and data processing of X-SAR. ##### |
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Global View of the Arctic Oc
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The Arctic Ocean has been ma
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8/21/00
| Date |
8/21/00 |
| Description |
The Arctic Ocean has been mapped in an unprecedented manner by scientists at NASA's Jet Propulsion Laboratory (JPL), Pasadena, Calif. Using advanced radar that sees through all weather conditions, researchers will now be able to determine how the Earth's warming may be changing the sea ice cover. Sea ice in the polar region is a large barometer of global climate conditions. The mission is a joint project between JPL and the Alaska Synthetic Aperture Radar Facility, University of Alaska, Fairbanks. JPL manages the Sea Ice Thickness Derived from High Resolution Radar Imagery project for NASA's Earth Science Enterprise, Washington, DC. The Earth Science Enterprise is dedicated to studying how natural and human-induced change affects our global environment. This image is posted on the World Wide Web at http://www.jpl.nasa.gov/pictures/seaice . |
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Comparative Views of Arctic
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Scientists at NASA's Jet Pro
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8/21/00
| Date |
8/21/00 |
| Description |
Scientists at NASA's Jet Propulsion Laboratory (JPL) have used high resolution radar to see, for the first time ever, the development of the Arctic sea ice cover. The images show a comparison of ice growth during the Arctic winter. The two images are separated by nine days. Both images represent an area located in the Baufort Sea, north of the Alaskan coast. This radar view covers an area of 96 by 128 kilometers (60 by 80 miles). The brighter features are older thicker ice and the darker areas show young, recently formed ice. The earlier image is shown on the left. Within the nine-day span, large and extensive cracks in the ice cover have formed due to ice movement. These cracks expose the open ocean to the cold, frigid atmosphere where sea ice grows rapidly and thickens. Formation of sea ice in the Arctic Ocean affects the heat balance in the global atmosphere and ocean. The mission is a joint project between JPL and the Alaska Synthetic Aperture Radar Facility, University of Alaska, Fairbanks. JPL manages the Sea Ice Thickness Derived from High Resolution Radar Imagery project for NASA's Earth Science Enterprise, Washington, DC. The Earth Science Enterprise is dedicated to studying how natural and human-induced change affects our global environment. This image is available at http://www.jpl.nasa.gov/pictures/seaice . ##### |
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Titan Crater in Three Views
PIA07868
Saturn
Radar Imager, Visual and Inf
…
| Title |
Titan Crater in Three Views |
| Original Caption Released with Image |
. For more information about the visual and infrared mapping spectrometer visit http://wwwvims.lpl.arizona.edu/ [ http://wwwvims.lpl.arizona.edu/ ]., Figure 1: Titan Crater in Three Views This three-panel image shows one of Titan's most prominent impact craters in an infrared-wavelength image (left), radar image (center) and in the false-color image (right). The Cassini radar imaged this crater during Cassini's third flyby of Titan, on Feb. 15, 2005, (see PIA07368 [ http://photojournal.jpl.nasa.gov/catalog/PIA07368 ]). The crater, located at 16 degrees west, 11 degrees north, is about 80 kilometers (50 miles) in diameter and is surrounded beyond that by a blanket of material thrown out of the crater during impact. In radar, brighter surfaces mean rougher terrains, or else terrains tilted toward the radar. Two Titan flybys later, on April 16, the visual infrared mapping spectrometer on Cassini obtained images of the same crater. The panel on the left is an image at the 2.0 micron wavelength, showing that the crater has a dark floor and a small bright area in the center. The crater is surrounded by bright material, which has a very faint halo slightly darker than the surrounding dark material. Compare the radar image with the visual infrared mapping spectrometer image. Both the crater and the blanket of surrounding material (called ejecta) are bright at radar wavelengths, in the infrared, the crater itself is dark and this blanket of material is quite bright. In radar, the faint halo surrounding the blanket of material is quite similar in appearance to the rest of the ejecta blanket. The right hand panel is a false-color visual infrared mapping spectrometer image of the crater at lower resolution. It shows the faint halo to be slightly bluer than surrounding material. That the material is bluer than its surroundings, while also being darker, suggests that the faint halo is somewhat different in composition. This suggests that the composition of Titan's upper crust varies with depth, and various materials were excavated when the crater was formed. The same structure appearing so different to different instruments illustrates the importance of multiple instruments studying such phenomena. The Cassini spacecraft, being the most interdisciplinary spacecraft ever flown, strongly embodies such an approach. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The radar instrument team is based at JPL, working with team members from the United States and several European countries. The visual and infrared mapping spectrometer team is based at the University of Arizona, Tucson. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ] |
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Titan Crater in Three Views
PIA07868
Saturn
Radar Imager, Visual and Inf
…
| Title |
Titan Crater in Three Views |
| Original Caption Released with Image |
. For more information about the visual and infrared mapping spectrometer visit http://wwwvims.lpl.arizona.edu/ [ http://wwwvims.lpl.arizona.edu/ ]., Figure 1: Titan Crater in Three Views This three-panel image shows one of Titan's most prominent impact craters in an infrared-wavelength image (left), radar image (center) and in the false-color image (right). The Cassini radar imaged this crater during Cassini's third flyby of Titan, on Feb. 15, 2005, (see PIA07368 [ http://photojournal.jpl.nasa.gov/catalog/PIA07368 ]). The crater, located at 16 degrees west, 11 degrees north, is about 80 kilometers (50 miles) in diameter and is surrounded beyond that by a blanket of material thrown out of the crater during impact. In radar, brighter surfaces mean rougher terrains, or else terrains tilted toward the radar. Two Titan flybys later, on April 16, the visual infrared mapping spectrometer on Cassini obtained images of the same crater. The panel on the left is an image at the 2.0 micron wavelength, showing that the crater has a dark floor and a small bright area in the center. The crater is surrounded by bright material, which has a very faint halo slightly darker than the surrounding dark material. Compare the radar image with the visual infrared mapping spectrometer image. Both the crater and the blanket of surrounding material (called ejecta) are bright at radar wavelengths, in the infrared, the crater itself is dark and this blanket of material is quite bright. In radar, the faint halo surrounding the blanket of material is quite similar in appearance to the rest of the ejecta blanket. The right hand panel is a false-color visual infrared mapping spectrometer image of the crater at lower resolution. It shows the faint halo to be slightly bluer than surrounding material. That the material is bluer than its surroundings, while also being darker, suggests that the faint halo is somewhat different in composition. This suggests that the composition of Titan's upper crust varies with depth, and various materials were excavated when the crater was formed. The same structure appearing so different to different instruments illustrates the importance of multiple instruments studying such phenomena. The Cassini spacecraft, being the most interdisciplinary spacecraft ever flown, strongly embodies such an approach. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The radar instrument team is based at JPL, working with team members from the United States and several European countries. The visual and infrared mapping spectrometer team is based at the University of Arizona, Tucson. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov [ http://saturn.jpl.nasa.gov ] |
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