fbpx
Wikipedia

Seasat

January 31, 2023

Seasat[3] was the first Earth-orbiting satellite designed for remote sensing of the Earth's oceans and had on board one of the first spaceborne synthetic-aperture radar (SAR). The mission was designed to demonstrate the feasibility of global satellite monitoring of oceanographic phenomena and to help determine the requirements for an operational ocean remote sensing satellite system. Specific objectives were to collect data on sea-surface winds, sea-surface temperatures, wave heights, internal waves, atmospheric water, sea ice features and ocean topography. Seasat was managed by NASA's Jet Propulsion Laboratory and was launched on 27 June 1978 into a nearly circular 800 km (500 mi) orbit with an inclination of 108°.[2] Seasat operated until 10 October 1978 (UTC),[1] when a massive short circuit in the Agena-D bus electrical system ended the mission.[4]

Seasat
Seasat
Mission typeOceanography
OperatorNASA / JPL / Caltech
COSPAR ID1978-064A
SATCAT no.10967
Mission duration105 days
Spacecraft properties
BusAgena-D
ManufacturerLockheed
Ball Aerospace
JPL
Launch mass2,290 kg (5,050 lb)[1]
Power700 watts[1]
Start of mission
Launch date27 June 1978, 01:12 (1978-06-27UTC01:12) UTC
RocketAtlas E/F Agena-D
Launch siteVandenberg SLC-3W
End of mission
Last contact10 October 1978 (1978-10-11) UTC[1]
Orbital parameters
Reference systemGeocentric
RegimeSun-synchronous
Eccentricity0.00209
Perigee altitude769 kilometers (478 mi)
Apogee altitude799 kilometers (496 mi)
Inclination108.0 degrees
Period100.7 minutes
Epoch26 June 1978, 21:12:00 UTC[2]
Instruments
Instruments
ALTRadar Altimeter
LRRLaser Retro-Reflector
SARSynthetic Aperture Radar
SASSSeaSat-A Scatterometer System
SMMRScanning Multichannel Microwave Radiometer
VIRRVisible and Infrared Radiometer
 

Instruments

Seasat carried five major instruments designed to return the maximum information from ocean surfaces:

  1. Radar altimeter to measure spacecraft height above the ocean surface
  2. Microwave scatterometer to measure wind speed and direction
  3. Scanning multichannel microwave radiometer to measure sea surface temperature
  4. Visible and infrared radiometer to identify cloud, land and water features
  5. Synthetic aperture radar (SAR) L-band, HH polarization, fixed look angle to monitor the global surface wave field and polar sea ice conditions {the antenna is the light parallelogram in the picture}. The SAR support structure was designed and manufactured by Northrop Grumman Astro Aerospace in Carpinteria, California. The structure deployed on orbit.

Many later remote sensing missions benefited from Seasat's legacy. These include imaging radars flown on NASA's Space Shuttle, altimeters on Earth-orbiting satellites such as TOPEX/Poseidon, and scatterometers on ADEOS I, QuikSCAT, and Jason-1.

2013 data release

On the 35th anniversary of Seasat's launch, the Alaska Satellite Facility released newly digitized Seasat synthetic aperture radar (SAR) imagery.[5] Until this release, Seasat SAR data were archived on magnetic tapes, and images processed from the tapes were available only as optical images of film strips or scanned digital images. Neither the tapes nor the film allow the quantitative analysis possible with the new digital archive.[6][7]

Conspiracy theory

Seasat is claimed to have been able to detect the wakes of submerged submarines. This supposed capability was unexpected.[8] The conspiracy theory holds that when this capability was discovered, the mission was ended for national security reasons, and the end of the mission was falsely blamed on catastrophic failure of the satellite's electric power system.[9][10] Subsequent ocean-observing SAR satellites with higher resolutions and sensitivities have not exhibited this claimed capability.

See also

References

  1. ^ a b c d "Satellite:SeaSat". Observing Systems Capability Analysis and Review Tool. World Meteorological Organization. 29 July 2015. Retrieved 3 June 2019.
  2. ^ a b "Spacecraft - Telemetry Details". NASA Space Science Data Coordinated Archive. Retrieved 30 April 2018.
  3. ^ . NASA Jet Propulsion Laboratory. Archived from the original on 20 July 2014. Retrieved 28 June 2013.
  4. ^ "Report of the Seasat Failure Review Board" (PDF). Readings in Systems Engineering. NASA Scientific and Technical Information Program: 201–215. 1993. Bibcode:1993rse..nasa..201. NASA-SP-6102; N93-24678.
  5. ^ Buis, Alan (27 June 2013). "Trailblazer Sea Satellite Marks Its Coral Anniversary". NASA Jet Propulsion Laboratory. Retrieved 28 June 2013.
  6. ^ Rettig, Molly (22 June 2013). "Old satellite imagery offers new baseline data". Anchorage Daily News. Archived from the original on 29 June 2013.
  7. ^ . University of Alaska Fairbanks. Archived from the original on 8 July 2013. Retrieved 28 June 2013.
  8. ^ Broad, William J. (11 May 1999). "U.S. Loses Hold on Submarine-Exposing Radar Technique". The New York Times. Retrieved 3 June 2019.
  9. ^ Norris, Pat (2008). Spies in the Sky: Surveillance Satellites in War and Peace. Springer Praxis Books. Praxis. p. 172. doi:10.1007/978-0-387-71673-2. ISBN 978-0-387-71672-5.
  10. ^ "Submarine detection from space". The Ship Model Forum. Retrieved 18 November 2008.

Further reading

  • Born, G. H.; et al. (29 June 1979). "Seasat Mission Overview". Science. 204 (4400): 1405–1406. Bibcode:1979Sci...204.1405B. doi:10.1126/science.204.4400.1405. PMID 17814195. S2CID 29178684.
  • "Special Issue on the SeaSat-1 Sensors". IEEE Journal of Oceanic Engineering. OE-5 (2). April 1980.
  • Elachi, C. (5 September 1980). "Spaceborne Imaging Radar: Geologic and Oceanographic Applications". Science. 209 (4461): 1073–1082. Bibcode:1980Sci...209.1073E. doi:10.1126/science.209.4461.1073. PMID 17841450. S2CID 11852573.
  • Fu, Lee-Lueng; Holt, Benjamin (15 February 1982). (PDF) (Report). NASA/Jet Propulsion Laboratory. JPL Pub. 81-120. Archived from the original (PDF) on 25 January 2017.
  • Case, K.; et al. (March 1984). Seasat Report (PDF) (Report). JASON. JSR-83-203.
  • Case, K.; et al. (August 1984). Seasat III & IV (PDF) (Report). JASON. JSR-84-203.

External links

 
Wikimedia Commons has media related to Seasat.
  • by the Jet Propulsion Laboratory
  • Seasat portal by the Alaska Satellite Facility

January 31, 2023
seasat, first, earth, orbiting, satellite, designed, remote, sensing, earth, oceans, board, first, spaceborne, synthetic, aperture, radar, mission, designed, demonstrate, feasibility, global, satellite, monitoring, oceanographic, phenomena, help, determine, re. Seasat 3 was the first Earth orbiting satellite designed for remote sensing of the Earth s oceans and had on board one of the first spaceborne synthetic aperture radar SAR The mission was designed to demonstrate the feasibility of global satellite monitoring of oceanographic phenomena and to help determine the requirements for an operational ocean remote sensing satellite system Specific objectives were to collect data on sea surface winds sea surface temperatures wave heights internal waves atmospheric water sea ice features and ocean topography Seasat was managed by NASA s Jet Propulsion Laboratory and was launched on 27 June 1978 into a nearly circular 800 km 500 mi orbit with an inclination of 108 2 Seasat operated until 10 October 1978 UTC 1 when a massive short circuit in the Agena D bus electrical system ended the mission 4 SeasatSeasatMission typeOceanographyOperatorNASA JPL CaltechCOSPAR ID1978 064ASATCAT no 10967Mission duration105 daysSpacecraft propertiesBusAgena DManufacturerLockheedBall AerospaceJPLLaunch mass2 290 kg 5 050 lb 1 Power700 watts 1 Start of missionLaunch date27 June 1978 01 12 1978 06 27UTC01 12 UTCRocketAtlas E F Agena DLaunch siteVandenberg SLC 3WEnd of missionLast contact10 October 1978 1978 10 11 UTC 1 Orbital parametersReference systemGeocentricRegimeSun synchronousEccentricity0 00209Perigee altitude769 kilometers 478 mi Apogee altitude799 kilometers 496 mi Inclination108 0 degreesPeriod100 7 minutesEpoch26 June 1978 21 12 00 UTC 2 InstrumentsInstrumentsALTRadar AltimeterLRRLaser Retro ReflectorSARSynthetic Aperture RadarSASSSeaSat A Scatterometer SystemSMMRScanning Multichannel Microwave RadiometerVIRRVisible and Infrared Radiometer Contents 1 Instruments 2 2013 data release 3 Conspiracy theory 4 See also 5 References 6 Further reading 7 External linksInstruments EditSeasat carried five major instruments designed to return the maximum information from ocean surfaces Radar altimeter to measure spacecraft height above the ocean surface Microwave scatterometer to measure wind speed and direction Scanning multichannel microwave radiometer to measure sea surface temperature Visible and infrared radiometer to identify cloud land and water features Synthetic aperture radar SAR L band HH polarization fixed look angle to monitor the global surface wave field and polar sea ice conditions the antenna is the light parallelogram in the picture The SAR support structure was designed and manufactured by Northrop Grumman Astro Aerospace in Carpinteria California The structure deployed on orbit Many later remote sensing missions benefited from Seasat s legacy These include imaging radars flown on NASA s Space Shuttle altimeters on Earth orbiting satellites such as TOPEX Poseidon and scatterometers on ADEOS I QuikSCAT and Jason 1 2013 data release EditOn the 35th anniversary of Seasat s launch the Alaska Satellite Facility released newly digitized Seasat synthetic aperture radar SAR imagery 5 Until this release Seasat SAR data were archived on magnetic tapes and images processed from the tapes were available only as optical images of film strips or scanned digital images Neither the tapes nor the film allow the quantitative analysis possible with the new digital archive 6 7 Conspiracy theory EditSeasat is claimed to have been able to detect the wakes of submerged submarines This supposed capability was unexpected 8 The conspiracy theory holds that when this capability was discovered the mission was ended for national security reasons and the end of the mission was falsely blamed on catastrophic failure of the satellite s electric power system 9 10 Subsequent ocean observing SAR satellites with higher resolutions and sensitivities have not exhibited this claimed capability See also EditGladys West project manager for Seasat Quill satellite first spaceborne SARReferences Edit a b c d Satellite SeaSat Observing Systems Capability Analysis and Review Tool World Meteorological Organization 29 July 2015 Retrieved 3 June 2019 a b Spacecraft Telemetry Details NASA Space Science Data Coordinated Archive Retrieved 30 April 2018 Seasat Mission Summary NASA Jet Propulsion Laboratory Archived from the original on 20 July 2014 Retrieved 28 June 2013 Report of the Seasat Failure Review Board PDF Readings in Systems Engineering NASA Scientific and Technical Information Program 201 215 1993 Bibcode 1993rse nasa 201 NASA SP 6102 N93 24678 Buis Alan 27 June 2013 Trailblazer Sea Satellite Marks Its Coral Anniversary NASA Jet Propulsion Laboratory Retrieved 28 June 2013 Rettig Molly 22 June 2013 Old satellite imagery offers new baseline data Anchorage Daily News Archived from the original on 29 June 2013 Alaska Satellite Facility Celebrates Seasat 35th Anniversary University of Alaska Fairbanks Archived from the original on 8 July 2013 Retrieved 28 June 2013 Broad William J 11 May 1999 U S Loses Hold on Submarine Exposing Radar Technique The New York Times Retrieved 3 June 2019 Norris Pat 2008 Spies in the Sky Surveillance Satellites in War and Peace Springer Praxis Books Praxis p 172 doi 10 1007 978 0 387 71673 2 ISBN 978 0 387 71672 5 Submarine detection from space The Ship Model Forum Retrieved 18 November 2008 Further reading EditBorn G H et al 29 June 1979 Seasat Mission Overview Science 204 4400 1405 1406 Bibcode 1979Sci 204 1405B doi 10 1126 science 204 4400 1405 PMID 17814195 S2CID 29178684 Special Issue on the SeaSat 1 Sensors IEEE Journal of Oceanic Engineering OE 5 2 April 1980 Elachi C 5 September 1980 Spaceborne Imaging Radar Geologic and Oceanographic Applications Science 209 4461 1073 1082 Bibcode 1980Sci 209 1073E doi 10 1126 science 209 4461 1073 PMID 17841450 S2CID 11852573 Fu Lee Lueng Holt Benjamin 15 February 1982 Seasat Views Oceans and Sea Ice with Synthetic Aperture Radar PDF Report NASA Jet Propulsion Laboratory JPL Pub 81 120 Archived from the original PDF on 25 January 2017 Case K et al March 1984 Seasat Report PDF Report JASON JSR 83 203 Case K et al August 1984 Seasat III amp IV PDF Report JASON JSR 84 203 External links Edit Spaceflight portal Wikimedia Commons has media related to Seasat JPL Seasat webpage by the Jet Propulsion Laboratory Seasat portal by the Alaska Satellite Facility Retrieved from https en wikipedia org w index php title Seasat amp oldid 1069396035, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.