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Collection:
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NASA Planetary Photo Journal Collection
Collection
NASA Planetary Photo Journal Collection
Collection
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Title:
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The Geodesy Campaign
Title
The Geodesy Campaign
Title
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Original Caption Released with Image:
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Every day, Mars Global Surveyor (MGS) circles the red planet just over twelve times, and from their vantage point at 400 km altitude, the fisheye lenses of the Mars Orbiter Camera (MOC)Wide Angle (WA) cameras can see the entire surface. During typical operations, highly-summed two-color image strips are transmitted for each orbit and assembled into daily global weather maps, with a resolution of about 7.5 km (4.6 miles) per pixel. The small size and low resolution of these strips leaves most of the data bandwidth available for higher-priority Narrow Angle images. During May 1999, however, the Wide Angle cameras are being used instead to map the whole planet at the intrinsic resolution of the WA camera -- 230 meters (750 feet) per pixel. While the blue WA camera continues to capture the global map so that daily weather can still be monitored, the other WA camera (with the red filter) is building up swaths of full-resolution coverage. The Deep Space Network is tracking the spacecraft 24 hours a day during this geodesy campaign, and imaging data are being returned for about two-thirds of the time at 69 kbits/sec(somewhat faster than a 56K modem). During the other third of the time, the spacecraft is transmitting back to Earth one day's worth of recorded data from the other science instruments. Geodesy is the measurement of a planet's shape and the location of features on its surface. The intent of the geodesy campaign is to acquire, during a short period of time, simultaneous measurements by the Mars Orbiter Laser Altimeter (MOLA), the Radio Science (RS)investigation, and the MOC. MOLA observations provide precise, absolute measurements of a set of profiles around the planet, but their spacing is quite large relative to their resolution. RS measurements provide detailed information about the position of the spacecraft, critical to processing both the MOC and MOLA data. MOC provides both a higher resolution base map on which the other data can be overlain and, using stereoscopic measurements, provides the potential for a ten-fold improvement in the spatial resolution of the topography. Owing to the nature of the MGS orbit, the groundtrack returns to within about 30 km of a given orbit 88 orbits (about one week) later. Thus, it takes a week to build up global coverage at full resolution. Figure MOC2-127a
Original_Caption_Rel eased_with_Image
Every day, Mars Global Surveyor (MGS) circles the red planet just over twelve times, and from their vantage point at 400 km altitude, the fisheye lenses of the Mars Orbiter Camera (MOC)Wide Angle (WA) cameras can see the entire surface. During typical operations, highly-summed two-color image strips are transmitted for each orbit and assembled into daily global weather maps, with a resolution of about 7.5 km (4.6 miles) per pixel. The small size and low resolution of these strips leaves most of the data bandwidth available for higher-priority Narrow Angle images. During May 1999, however, the Wide Angle cameras are being used instead to map the whole planet at the intrinsic resolution of the WA camera -- 230 meters (750 feet) per pixel. While the blue WA camera continues to capture the global map so that daily weather can still be monitored, the other WA camera (with the red filter) is building up swaths of full-resolution coverage. The Deep Space Network is tracking the spacecraft 24 hours a day during this geodesy campaign, and imaging data are being returned for about two-thirds of the time at 69 kbits/sec(somewhat faster than a 56K modem). During the other third of the time, the spacecraft is transmitting back to Earth one day's worth of recorded data from the other science instruments. Geodesy is the measurement of a planet's shape and the location of features on its surface. The intent of the geodesy campaign is to acquire, during a short period of time, simultaneous measurements by the Mars Orbiter Laser Altimeter (MOLA), the Radio Science (RS)investigation, and the MOC. MOLA observations provide precise, absolute measurements of a set of profiles around the planet, but their spacing is quite large relative to their resolution. RS measurements provide detailed information about the position of the spacecraft, critical to processing both the MOC and MOLA data. MOC provides both a higher resolution base map on which the other data can be overlain and, using stereoscopic measurements, provides the potential for a ten-fold improvement in the spatial resolution of the topography. Owing to the nature of the MGS orbit, the groundtrack returns to within about 30 km of a given orbit 88 orbits (about one week) later. Thus, it takes a week to build up global coverage at full resolution. Figure MOC2-127a Original Caption Released with Image
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Original Caption Released with Image:
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shows the planning map of coverage during the first week of the campaign (top), and the resulting actual coverage (bottom). Gaps caused by recorder playbacks must be filled in a second week of imaging by moving the times of the playbacks. Also in the second week, stereo coverage is acquired by re-imaging areas from adjacent orbits at aside-looking angle. Figure MOC2-127b shows an example of such stereo from the Mare Tyrrhenum region, centered at 27.3°S, 227.0°W (NOTE: Red-blue glasses are needed to view the stereo effect). The crater that dominates the center of Figure MOC2-127b is about 50 kilometers (31 miles) across. Stereo coverage will be completed in the third and fourth weeks. The remaining data volume will be used to fill in gaps created by data losses, and to acquire a somewhat lower resolution global color image through the blue wide angle camera.
The resulting dataset will provide global color and stereo coverage at about 300 m/pixel. Although similar coverage was obtained by the Viking mission in the late 1970s, Viking took over three years to cover the planet, and there are significant variations in lighting, weather, and surface features in the Viking images. A substantial improvement in the longitude/latitude grid is expected, which will have important benefits to future Mars exploration.
Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
Original_Caption_Rel eased_with_Image
shows the planning map of coverage during the first week of the campaign (top), and the resulting actual coverage (bottom). Gaps caused by recorder playbacks must be filled in a second week of imaging by moving the times of the playbacks. Also in the second week, stereo coverage is acquired by re-imaging areas from adjacent orbits at aside-looking angle. Figure MOC2-127b shows an example of such stereo from the Mare Tyrrhenum region, centered at 27.3°S, 227.0°W (NOTE: Red-blue glasses are needed to view the stereo effect). The crater that dominates the center of Figure MOC2-127b is about 50 kilometers (31 miles) across. Stereo coverage will be completed in the third and fourth weeks. The remaining data volume will be used to fill in gaps created by data losses, and to acquire a somewhat lower resolution global color image through the blue wide angle camera.
The resulting dataset will provide global color and stereo coverage at about 300 m/pixel. Although similar coverage was obtained by the Viking mission in the late 1970s, Viking took over three years to cover the planet, and there are significant variations in lighting, weather, and surface features in the Viking images. A substantial improvement in the longitude/latitude grid is expected, which will have important benefits to future Mars exploration.
Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.
Original Caption Released with Image
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Addition Date:
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1999-05-17
Addition_Date
1999-05-17
Addition Date
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Image Credit:
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NASA/JPL/MSSS
Image_Credit
NASA/JPL/MSSS
Image Credit
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Produced By:
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Malin Space Science Systems
Produced_By
Malin Space Science Systems
Produced By
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Mission:
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Mars Global Surveyor (MGS)
Mission
Mars Global Surveyor (MGS)
Mission
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Spacecraft:
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Mars Global Surveyor Orbiter
Spacecraft
Mars Global Surveyor Orbiter
Spacecraft
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Target Name:
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Mars
Target_Name
Mars
Target Name
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Is a satellite of:
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Sol (our sun)
Is_a_satellite_of
Sol (our sun)
Is a satellite of
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Instrument:
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Mars Orbiter Camera
Instrument
Mars Orbiter Camera
Instrument
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Product Size:
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685 samples x 856 lines
Product_Size
685 samples x 856 lines
Product Size
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Primary Data Set:
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MGS EDRs
Primary_Data_Set
MGS EDRs
Primary Data Set
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Producer ID:
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MOC2-127B
P50382
MRPS94895
Producer_ID
MOC2-127B
P50382
MRPS94895
Producer ID
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facet_what:
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Sun
facet_what
Sun
facet_what
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facet_what:
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Crater
facet_what
Crater
facet_what
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facet_what:
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Earth
facet_what
Earth
facet_what
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facet_what:
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Mars
facet_what
Mars
facet_what
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facet_what:
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Viking
facet_what
Viking
facet_what
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facet_what:
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Deep Space Network
facet_what
Deep Space Network
facet_what
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facet_what:
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Altimeter
facet_what
Altimeter
facet_what
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facet_what:
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STEREO
facet_what
STEREO
facet_what
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facet_what:
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Surveyor
facet_what
Surveyor
facet_what
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facet_what:
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Mars Observer
facet_what
Mars Observer
facet_what
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facet_what:
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Mars Global Surveyor Orbiter (MGS)
facet_what
Mars Global Surveyor Orbiter (MGS)
facet_what
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facet_what:
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Mars Orbiter Camera (MOC)
facet_what
Mars Orbiter Camera (MOC)
facet_what
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facet_what:
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Mars Orbiter Laser Altimeter (MOLA)
facet_what
Mars Orbiter Laser Altimeter (MOLA)
facet_what
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facet_where:
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Jet Propulsion Laboratory
facet_where
Jet Propulsion Laboratory
facet_where
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facet_where:
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Denver
facet_where
Denver
facet_where
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facet_where:
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Mars
facet_where
Mars
facet_where
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facet_where:
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California
facet_where
California
facet_where
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facet_where:
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Jet Propulsion Laboratory (JPL)
facet_where
Jet Propulsion Laboratory (JPL)
facet_where
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facet_when:
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May 1999
facet_when
May 1999
facet_when
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facet_when_year:
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1999
facet_when_year
1999
facet_when_year
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Image #:
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PIA02023
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UID:
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SPD-PHOTJ-PIA02023
UID
SPD-PHOTJ-PIA02023
UID
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orignial url:
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orignial_url
orignial url
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