Alaska Satellite Facility Explained

The Alaska Satellite Facility (ASF) is a data processing facility and satellite-tracking ground station within the Geophysical Institute at the University of Alaska Fairbanks.[1] The facility’s mission is to make remote-sensing data accessible[2] Its work is central to polar processes research including wetlands,[3] glaciers,[4] sea ice,[5] climate change, permafrost,[6] flooding and land cover such as changes in the Amazon rainforest.

History

The Alaska Satellite Facility began as a single-purpose receiving station known as the Alaska Synthetic Aperture Radar (SAR) Facility[7] located in the Geophysical Institute (GI) at the University of Alaska Fairbanks.[8] The interest in space-borne SAR observations began in the U.S. with the success of the Seasat mission in 1978.[9] (There is information below under "Data Center" about the facility's 2013 release of newly processed Seasat SAR data.) After Seasat’s premature demise,[10] scientists from the federally funded Jet Propulsion Laboratory and the Geophysical Institute developed the concept of a ground station in Fairbanks, Alaska, to receive data from foreign satellites.[11]

In 1986, the Jet Propulsion Laboratory requested and approved a quotation for the integration of a receiving ground station, the Alaska SAR Facility, at UAF.[12] The Alaska SAR Facility was marked at a ribbon-cutting ceremony on April 24, 1991. Later that year, the facility began down-linking European Remote Sensing Satellite-1 (ERS-1) data.[13] The expected data volume for the station was 45 minutes total from ERS-1, JERS-1 and RADARSAT. In the operations stage, data flow rapidly increased due to changing requirements from flight agencies and government sponsors, and storage of online data and demand for SAR data was expected to rapidly exceed capacity.[14] The Satellite-Tracking Ground Station launched in 1990,[15] and in 1994 a Memorandum of Agreement (MOA) between NASA and UAF formed the ASF Distributed Active Archive Center (DAAC). The facility was renamed the Alaska Satellite Facility in 2003.[16]

The ASF DAAC is one of 12[17] DAACs[18] funded by NASA to support earth observations from ground-based, in-situ, airborne, and space borne sensors. The ASF DAAC processes, distributes, and archives data products as assigned by NASA. The ASF DAAC archive now offers more than a dozen synthetic aperture radar (SAR) datasets.[19] Tasking and missions have been added or deleted from the MOA when deemed appropriate by NASA program managers, Goddard Space Flight Center (GSFC) personnel, and ASF management.

NASA, on behalf of the Canadian Space Agency, launched RADARSAT-1 in November 1995. At this point, ASF was handling data from the original three satellite missions that spurred the science community into envisioning this facility. The launch of ADEOS-1 resulted in ASF simultaneously supporting four active missions until the loss of the two Japanese missions (ADEOS-1 in 1996 and JERS-1 in 1998), and the deactivation of ERS-1 with the launch of ERS-2 in 1996. In November 2002, the National Oceanic and Atmospheric Administration (NOAA) appointed UAF as agent[20] for the data acquisition, processing, and distribution to support the Japanese Advanced Land Observing Satellite (ALOS) mission, which featured Phased Array L-band Synthetic Aperture Radar (PALSAR). With the successful launch of ALOS in January 2006, ASF’s Americas ALOS Data Node (AADN)[21] became operational in October that same year when the Japan Aerospace Exploration Agency (JAXA) declared the ALOS mission operational. The satellite functioned for five years.

Data center

The ASF DAAC provides production, archiving and distribution to the scientific community of synthetic aperture radar (SAR) data products and tools from active and past missions. The facility is one of 12 theme-based National Aeronautics and Space Administration (NASA) earth science data centers in the nation known as NASA Distributed Active Archive Centers (DAACs). The DAACs are major components of the Earth Observing System Data and Information System (EOSDIS), which in turn is part of NASA’s Earth Science Data Systems Program.[22]

The Alaska Satellite Facility is the only DAAC that focuses on SAR. It is also the U.S. archive[23] for Sentinel-1A and Sentinel-1B (a European Space Agency mission),[24] European Remote Sensing Satellite 1 and 2 (ERS 1/ERS 2), the Japanese Earth Resources Satellite 1 (JERS 1), RADARSAT 1 and the Japanese Advanced Land Observing Satellite (ALOS) mission, which featured Phased Array L-band Synthetic Aperture Radar (PALSAR[25]). Due to the agreements with many of the foreign agencies involved, at first much of the foreign-source DAAC data was restricted distribution[26] to NASA-approved scientists only.[27] But in 2015, the ALOS PALSAR data became unrestricted,[28] and the Sentinel-1 data is also unrestricted.[19]

In June 2013, the Alaska Satellite Facility released newly processed, 35-year-old data[29] from the 1978 Seasat satellite mission.[30] Before this release, only 20 percent of the Seasat SAR data had been processed digitally.[31]

Satellite-tracking ground station

As a receiving station for satellite data, the facility now operates three antennas on behalf of NASA: two 11-meter S/X band antennas and one 9-meter S/X-band.[32] [33] The second antenna was installed in 1994, in anticipation of the launch of the Advanced Earth Observing Satellite-1 (ADEOS-1) by Japan. The second 11-meter antenna[34] was installed in 1995 on University-owned land within walking distance from the Geophysical Institute, and the 9-meter antenna replaced the original ground-station antenna in 2017. The ground station's prime polar location[1] in Fairbanks enables the facility to service high-inclination, polar-orbiting, Earth-imaging spacecraft. The systems operate 24 hours a day, 7 days per week.[1] The facility has evolved over the past 20 years into a full-service station,[1] providing telemetry downlink, uplink, command and two-way coherent tracking services as one of 15 major members of the international Near Earth Network,[35] which is managed by NASA’s Goddard Space Flight Center. The facility processes, and distributes raw data[36] from remote-sensing satellites, servicing NASA and foreign agency satellites in support of scientific and operational research and applications.

GeoData center

The Alaska Satellite Facility managed the Geophysical Institute's GeoData Center for many years. In 2016, management of the center was transferred out of the Alaska Satellite Facility.[37] Its new website is here.

External links

Notes and References

  1. Web site: Arko. Scott. The Alaska Satellite Facility Ground Station. SpaceOps 2012: The 12th International Conference on Space Operations, Stockholm. 6 November 2013. etal.
  2. Web site: Alaska Satellite Facility. University of Alaska Fairbanks. 12 June 2013.
  3. An Inundated Wetlands Earth System Data Record: Global Monitoring of Wetland Extent and Dynamics. AGU Fall Meeting Abstracts. 2008. IN53B–07. NASA. 12 June 2013. https://web.archive.org/web/20121113134736/http://earthdata.nasa.gov/our-community/community-data-system-programs/measures-projects/global-monitoring-wetlands. 13 November 2012. dead. dmy-all. 2008AGUFMIN53B..07P. Podest. E.. McDonald. K.. Chapman. B.. Hess. L.. Moghaddam. M.. Kimball. J. S.. Matthews. E.. Prigent. C.. 2008.
  4. Web site: Hauser. Rachel. Glacier Power. NASA. 12 June 2013. https://web.archive.org/web/20150206135036/https://earthdata.nasa.gov/featured-stories/featured-research/glacier-power. 6 February 2015. dead. dmy-all.
  5. Web site: Varani. Annette. Ice Happens. NASA. 12 June 2013. https://web.archive.org/web/20150206135051/https://earthdata.nasa.gov/featured-stories/featured-research/ice-happens. 6 February 2015. dead. dmy-all.
  6. Web site: Beitler. Jane. Leaking lakes. 12 November 2012 . NASA. 12 June 2013.
  7. Book: Review of NASA's Distributed Active Archive Centers (1999), Commission on Geosciences, Environment and Resources. 1999 . The National Academies Press. 10.17226/6396 . 978-0-309-06331-9 . 12 June 2013.
  8. F. Carsey. The Alaska Synthetic Aperture Radar (SAR) Facility Project. Eos, Transactions American Geophysical Union. 68. 25. 593–596. etal. 10.1029/EO068i025p00593-01. 1987. 1987EOSTr..68Q.593C.
  9. Way. JoBea. The evolution of synthetic aperture radar systems and their progression to the EOS SAR. IEEE Transactions on Geoscience and Remote Sensing. 29. 6. 962–985. 12 June 2013. etal. 1991ITGRS..29..962W. 1991. 10.1109/36.101374.
  10. Book: Lundin, Bruce T. Report of the Seasat Failure Review Board (December 21, 1978). NASA. 12 June 2013. 1978-12-21.
  11. Web site: Message from the ASF Director. Winter 2012. University of Alaska Fairbanks. 27 June 2013.
  12. Web site: Aeronautics and Space Report of the President: 1985 Activities. 19. NASA. 12 June 2013.
  13. Web site: ERS-1 (European Remote-Sensing Satellite-1). eoPortal: Sharing Earth Observation Resources. 12 June 2013. https://archive.today/20130624190700/http://www.eoportal.org/directory/pres_ERS1EUROPEANREMOTESENSINGSATELLITE1.html. 24 June 2013. dead. dmy-all.
  14. Web site: Cuddy. David. Alaska SAR Facility Mass Storage, Current System (submit to Conference on Mass Storage Systems and Technologies) October 19-21,1993. Jet Propulsion Laboratory. 12 June 2013. etal. https://web.archive.org/web/20160305020136/http://trs-new.jpl.nasa.gov/dspace/bitstream/2014/35506/1/93-1181.pdf. 5 March 2016. dead. dmy-all.
  15. Book: Review of NASA's Distributed Active Archive Centers (1999) Commission on Geosciences, Environment and Resources (CGER). BOX 6.1. Vital Statistics of the ASF DAAC. 1999 . The National Academies Press. 10.17226/6396 . 978-0-309-06331-9 . 12 June 2013.
  16. Web site: Message from the ASF Director. News and Notes Winter 2012. University of Alaska Fairbanks. 27 June 2013.
  17. Web site: EOSDIS Distributed Active Archive Centers (DAACs) Earthdata. earthdata.nasa.gov. 2016-11-21.
  18. Book: Review of NASA's Distributed Active Archive Centers (1999) Commission on Geosciences, Environment and Resources (CGER). 1999 . National Academies Press. 10.17226/6396 . 978-0-309-06331-9 . 12 June 2013.
  19. Web site: Get Data / Get Started / How to Get SAR Data Alaska Satellite Facility. www.asf.alaska.edu. 2016-11-21.
  20. Arko. S.A.. Development and Operation of the Americas ALOS Data Node. 2004AGUFMSF43A0770A. Marlin. R. H.. La Belle-Hamer. A. L.. 43. 2004. SF43A–0770. AGU Fall Meeting Abstracts. etal.
  21. Web site: Atwood. Don. ASF: Supporting the ALOS Mission. National Snow and Ice Data Center, International Ice Chart Working Group. 12 June 2013.
  22. Web site: Earth Science Data. NASA. 12 June 2013.
  23. Web site: About SAR Data Center. University of Alaska Fairbanks. 12 June 2013.
  24. Web site: Global Sentinel-1A Data Available from ASF DAAC Earthdata. https://web.archive.org/web/20161104044629/https://earthdata.nasa.gov/global-sentinel-1a-data-available-from-asf-daac-2015-12-09. dead. 2016-11-04. earthdata.nasa.gov. 2016-11-21.
  25. Web site: SDC Supported Sensors. University of Alaska Fairbanks. 12 June 2013.
  26. Web site: EOSDIS. NASA. 27 June 2013. https://web.archive.org/web/20121003071553/http://earthdata.nasa.gov/data/data-centers/asf. 3 October 2012. dead. dmy-all.
  27. Web site: SAR Data Center: SDC Data. University of Alaska Fairbanks. 27 June 2013. https://web.archive.org/web/20130421052921/http://www.asf.alaska.edu/program/sdc/data. 21 April 2013. dead. dmy-all.
  28. Web site: An Unrestricted View: PALSAR Data at NASA's Alaska Satellite Facility Distributed Active Archive Center Are Now Easier to Access Earthdata. earthdata.nasa.gov. 2016-11-21. https://web.archive.org/web/20161121170743/https://earthdata.nasa.gov/unrestricted-palsar-asf-daac. 2016-11-21. dead.
  29. Web site: Seasat Rediscovered: New Imagery from 35-Year-Old Data . University of Alaska Fairbanks . 28 June 2013 . dead . https://web.archive.org/web/20130708151410/https://www-prod.asf.alaska.edu/seasat/ . 8 July 2013 .
  30. News: Rettig. Molly. Old satellite imagery offers new baseline data. 28 June 2013. Anchorage Daily News. 2013-06-22. https://archive.today/20130629093718/http://www.adn.com/2013/06/22/2947411/molly-rettig-old-satellite-imagery.html. 2013-06-29. dead.
  31. Web site: Trailblazer Sea Satellite Marks Its Coral Anniversary. NASA Jet Propulsion Laboratory. 28 June 2013.
  32. Web site: NASA's Newest Near Earth Network Antenna Is Operational. NASA.gov. 10 July 2014 . NASA. July 20, 2015.
  33. Web site: NASA's Near Earth Network (NEN) AS3 Antenna Deployment Project. NASA. 4 August 2016. https://web.archive.org/web/20150928213027/http://esc.gsfc.nasa.gov/assets/images/NEN%20AS3/NEN%20write-up.1.pdf. 2015-09-28. dead.
  34. Web site: NEN. NASA. 12 June 2013. https://web.archive.org/web/20130614152406/http://esc.gsfc.nasa.gov/space-communications/NEN/nen.html. 14 June 2013. dead. dmy-all.
  35. Web site: Near Earth Network. NASA. 12 June 2013.
  36. Web site: About STGS. University of Alaska Fairbanks. 12 June 2013.
  37. Web site: GeoData Center & Map Office Geophysical Institute. www.gi.alaska.edu. 2016-11-21. https://web.archive.org/web/20161121171520/http://www.gi.alaska.edu/administration/map-office. 2016-11-21. dead.