United States Naval Observatory Flagstaff Station Explained

See main article: United States Naval Observatory.

United States Naval Observatory Flagstaff Station
Organization:United States Naval Observatory
Location:Coconino County, near Flagstaff, Arizona
Coords:35.1842°N -111.7406°W
Established:1955
Telescope1 Name:Kaj Strand Telescope
Telescope1 Type:1.55 m (61 in) reflector
Telescope2 Name:DFM/Kodak/Corning
Telescope2 Type:1.3 m reflector
Telescope3 Name:Unnamed telescope
Telescope3 Type:1.0 m (40 in) Ritchey–Chrétien reflector
Telescope4 Name:Flagstaff Astrometric Scanning Transit Telescope
Telescope4 Type:8inches catadioptric
Telescope5 Name:Navy Precision Optical Interferometer
Telescope5 Type:interferometer (Located at Anderson Mesa)
Website:United States Naval Observatory's Flagstaff Station

The United States Naval Observatory Flagstaff Station (NOFS), is an astronomical observatory near Flagstaff, Arizona, US. It is the national dark-sky observing facility under the United States Naval Observatory (USNO).[1] NOFS and USNO combine as the Celestial Reference Frame[2] manager for the U.S. Secretary of Defense.[3] [4]

General information

The Flagstaff Station is a command which was established by USNO (due to a century of eventually untenable light encroachment in Washington, D.C.) at a site 5miles west of Flagstaff, Arizona in 1955, and has positions for primarily operational scientists (astronomers and astrophysicists), optical and mechanical engineers, and support staff.

NOFS science supports every aspect of positional astronomy to some level, providing national support and beyond. Work at NOFS covers the gamut of astrometry and astrophysics in order to facilitate its production of accurate/precise astronomical catalogs. Also, owing to the celestial dynamics (and relativistic effects[5]) of the huge number of such moving objects across their own treks through space, the time expanse required to pin down each set of celestial locations and motions for a perhaps billion-star catalog, can be quite long. Multiple observations of each object may themselves take weeks, months or years, by themselves. This, multiplied by the large number of cataloged objects that must then be reduced for use, and which must be analyzed after observation for a very careful statistical understanding of all catalog errors, forces the rigorous production of most extremely precise and faint astrometric catalogs to take many years, sometimes decades, to complete.

The United States Naval Observatory, Flagstaff Station celebrated its 50th anniversary of the move there from Washington, D.C. in late 2005.[6] Dr. John Hall, Director of the Naval Observatory's Equatorial Division from 1947, founded NOFS. Dr. Art Hoag became its first director in 1955 (until 1965); both later were to also become directors of nearby Lowell Observatory.[7] NOFS has had 6 directors since 1955; its current and 7th acting director is Dr. Scott Dahm.[8]

NOFS remains active in supporting regional dark skies,[9] [10] both to support its national protection mission,[11] [12] and to promote and protect a national resource legacy for generations of humans to come.[13] [14] [15]

Site description

NOFS is adjacent to Northern Arizona's San Francisco Peaks, on the alpine Colorado Plateau and geographically above the Mogollon Rim. Flagstaff and Coconino County minimize northern Arizona light pollution[16] through legislation of progressive code – which regulates local lighting.[17] [18] [19] [20]

Indeed, despite a half-century-young history, NOFS has a rich heritage[21] which is derived from its parent organization, USNO, the oldest scientific institution in the U.S.[22] Notable events have included support to the Apollo Astronaut program hosted by USGS' nearby Astrogeology Research Center; and the discovery of Pluto's moon, Charon, in 1978 (discussed below). At an elevation of approximately 7500feet, NOFS is home to a number of astronomical instruments[23] (some also described in the worldwide list of optical telescopes); some additional instrumentation is on nearby Anderson Mesa. NOFS (with parent USNO) also do fundamental science on the UKIRT Infrared telescope in Hawaii.

The Navy provides stewardship of the facility, land and related dark sky protection efforts through its Navy Region Southwest, through Naval Air Facility El Centro.

Kaj Strand Telescope

The 1.55m (05.09feet) Kaj Strand Telescope (or Kaj Strand Astrometric Reflector, KSAR) remains the largest telescope operated by the U.S. Navy. Congress appropriated funding in 1961 and it saw first light in 1964.[24] This status will change when the NPOI four 1.8-meter telescopes see their own first light in the near future. KSAR rides in the arms of an equatorial fork mount. The telescope is used in both the visible spectrum, and in the near infrared (NIR),[25] the latter using a sub-30-kelvin, helium-refrigerated, InSb (Indium antimonide) camera, "Astrocam".[26] In 1978, the 1.55-m telescope was used to "discover the moon of dwarf planet Pluto, named 'Charon'". (Pluto itself was discovered in 1930, across town at Lowell Observatory). The Charon discovery led to mass calculations which ultimately revealed how tiny Pluto was, and eventually caused the IAU to reclassify Pluto as a dwarf (not a principal) planet.[27] [28] [29] The 1.55-meter telescope was also used to observe and track NASA's Deep Impact Spacecraft, as it navigated to a successful inter-planetary impact with the celebrated Comet 9p/Tempel, in 2005. This telescope is particularly well-suited to perform stellar parallax studies, narrow-field astrometry supporting space navigation, and has also played a key role in discovering one of the coolest-ever known brown dwarf objects, in 2002.[30] The KSAR dome is centrally located on NOFS grounds, with support and office buildings attached to the dome structures. The large vacuum coating chamber facility is also located in this complex. The chamber can provide very accurate coatings and overcoatings of Angstrom thickness (approximately 56 aluminium atoms thick), for small-to-multi-ton optics up to 72inches in diameter, in a vacuum exceeding, using a vertical-optic, 1500-ampere discharge system. A dielectric coating capability has also been demonstrated. Large optics and telescope components can be moved about NOFS using its suite of cranes, lifts, cargo elevators and specialized carts. The main complex also contains a controlled-environment, optical and electronics lab for laser, adaptive optics, optics development, collimation, mechanical, and micro-electronic control systems needed for NOFS and NPOI.

The KSAR Telescope's 60feet diameter steel dome is quite large for the telescope's aperture, owing to its telescope's long f/9.8 focal ratio (favorable for very accurate optical collimation, or alignment, needed for astrometric observation). It uses a very wide 2-shutter, vertical slit. Development studies have taken place to successfully show that planned life-cycle replacement of this venerable instrument can be efficiently done within the original dome, for a future telescope with an aperture of up to 3.6m (11.8feet), by using fast, modern-day optics. However, the 61-inch telescope remains unique in its ability to operationally conduct both very high-accuracy relative astrometry to the milliarcsecond level, and close-separation, PSF photometry. Several key programs take advantage of this capability to this day.

1.3-m telescope

The 1.3m (04.3feet) large-field Ritchey–Chrétien telescope was produced by DFM Engineering and then corrected and automated by NOFS staff.[31] Corning Glass Works and Kodak made the primary mirror. The hyperbolic secondary has an advanced, computer-controlled collimation (alignment) system in order to permit very precise positions of stars and satellites (milliarcsecond astrometry) across its wide field of view. This system analyzes optical aberrations of the optical path, modeled by taking slope fits of the wavefront deviations revealed using a Hartmann mask. The telescope also now sports a state-of-the art, cryogenic wide-field mosaic CCD[32] camera.[33] [34] It will also permit employment of the new "Microcam", an orthogonal transfer array (OTA), with Pan-STARRS heritage.[35] [36] [37] [38] Other advanced camera systems are also deployed for use on this telescope, such as the LANL-produced RULLI single photon counter, nCam.[39] [40] [41] [42] Using the telescope's special software controls, the telescope can track both stars and artificial satellites orbiting the Earth, while the camera images both. The 1.3 m dome itself is compact, owing to the fast overall optics at f/4. It is located near by and southwest of, the very large 61-inch dome. In addition to astrometric studies (such as for Space Situational Awareness, SDSS[43] and SST), research on this telescope includes the study of blue and K-Giant stars, celestial mechanics and dynamics of multiple star systems, characterizations of artificial satellites, and the astrometry and transit photometry of exoplanets.

1.0-m telescope

The 40inches "Ritchey–Chrétien Telescope" is also an equatorially driven, fork-mounted telescope.[44] The Ritchey is the original Station telescope which was moved from USNO in Washington in 1955. It is also the first R-C telescope ever made from that famous optical prescription, and was coincidentally the last telescope built by George Ritchey himself. The telescope is still in operation after a half century of astronomy at NOFS. It performs key quasar-based reference frame operations (International Celestial Reference Frame), transit detections of exoplanets, Vilnius photometry, M-Dwarf star analysis, dynamical system analysis, reference support to orbiting space object information, horizontal parallax guide support to NPOI, and it performs photometric operations support to astrometric studies (along with its newer siblings). The 40-inch telescope can carry a number of liquid nitrogen-cooled cameras, a coronagraph, and a nine-stellar magnitude neutral density spot focal plane array camera, through which star positions are cross-checked before use in fundamental NPOI reference frame astrometry.

This telescope is also used to test internally developed optical adaptive optics (AO) systems, using tip-tilt and deformable mirror optics. The Shack–Hartmann AO system allows for corrections of the wavefront's aberrations caused by scintillation (degraded seeing), to higher Zernike polynomials. AO systems at NOFS will migrate to the 1.55-m and 1.8-m telescopes for future incorporation there.

The 40-inch dome is located at the summit and highest point of the modest mountain upon which NOFS is located. It is adjacent to a comprehensive instrumentation shop, which includes sophisticated, CAD-driven CNC fabrication machinery, and a broad array of design and support tooling.

0.2-m FASTT

A modern-day example of a fully robotic transit telescope is the small 8inches Flagstaff Astrometric Scanning Transit Telescope (FASTT) completed in 1981 and located at the observatory.[45] [46] FASTT provides extremely precise positions of solar system objects for incorporation into the USNO Astronomical Almanac and Nautical Almanac. These ephemerides are also used by NASA in the deep space navigation of its planetary and extra-orbital spacecraft.[47] Instrumental to the navigation of many NASA deep space probes, data from this telescope is responsible for NASA JPL's successful 2005 navigation-to-landing of the Huygens Lander on Titan, a major moon orbiting Saturn, and provided navigational reference for NASA's New Horizons deep space mission to Pluto, which arrived in July 2015. FASTT was also used to help NASA's SOFIA Airborne Observatory correctly locate, track and image a rare Pluto occultation.[48] FASTT is located 150abbr=offNaNabbr=off southwest of the primary complex. Attached to its large "hut" is the building housing NOFS' electronics and electrical engineering laboratories and clean rooms, where most of the advanced camera electronics, cryogenics and telescope control drives are developed and made.

Navy Precision Optical Interferometer

NOFS operates the Navy Precision Optical Interferometer (NPOI)[49] [50] in collaboration with Lowell Observatory and the Naval Research Laboratory at Anderson Mesa, 15miles south-east of Flagstaff. NOFS (the operational astrometric arm of USNO) funds all principle operations, and from this contracts Lowell Observatory to maintain the Anderson Mesa facility and make the observations necessary for NOFS to conduct the primary astrometric science. The Naval Research Laboratory (NRL) also provides additional funds to contract Lowell Observatory's and NRL's implementation of additional, long-baseline siderostat stations, facilitating NRL's primary scientific work, synthetic imaging (both celestial and of orbital satellites). The three institutions – USNO, NRL, and Lowell – each provide an executive to sit on an Operational Advisory Panel (OAP), which collectively guides the science and operations of the interferometer. The OAP commissioned the chief scientist and director of the NPOI to effect the science and operations for the Panel; this manager is a senior member of the NOFS staff and reports to the NOFS Director.

NPOI is a successful astronomical interferometer of the venerable and proven Michelson interferometer design. As noted, the majority of interferometric science and operations are funded and managed by NOFS; however, Lowell Observatory and NRL join in the scientific efforts through their fractions of time to use the interferometer; 85% Navy (NOFS and NRL); and 15% Lowell. NPOI is one of the few major instruments globally which can conduct optical interferometry.[51] See an illustration of its layout, at bottom. NOFS has used NPOI to conduct a wide and diverse series of scientific studies, beyond just the study of absolute astrometric positions of stars.[52] Additional NOFS science at NPOI includes the study of binary stars, Be stars, oblate stars, rapidly rotating stars, those with starspots, and the imaging of stellar disks (the first in history) and flare stars.[53] In 2007–2008, NRL with NOFS used NPOI to obtain first-ever closure phase image precursors of satellites orbiting in geostationary orbit.[54] [55]

See also

Notes and References

  1. Web site: The United States Naval Observatory (USNO) . Naval Oceanography Portal . 18 February 2016 . dead . https://web.archive.org/web/20160131231447/http://www.usno.navy.mil/USNO . 31 January 2016.
  2. George H. Kaplan . 2000 . A Random Walk Through Astrometry . Sixth DoD Astrometry Forum – 5–6 December 2000 Washington, DC . http://ad.usno.navy.mil/forum/forum.html . 18 February 2016 . live . https://web.archive.org/web/20120319234250/http://ad.usno.navy.mil/forum/kaplan1.pdf . 19 March 2012.
  3. Web site: The U.S. Naval Observatory: Mission, Products, and Services . Comet MetEd . 2013-11-14 . 22 July 2013 . https://web.archive.org/web/20130722135914/https://www.meted.ucar.edu/training_module.php?id=883 . live .
  4. Web site: OPNAV Instruction 9420.1B . M.J. Edwards . 29 June 2007 . 7 May 2012 . dead . https://web.archive.org/web/20130222090224/http://doni.daps.dla.mil/Directives/09000%20General%20Ship%20Design%20and%20Support/09-400%20Command%20and%20Surveillance%20Systems%20Support/9420.1B.pdf . 22 February 2013.
  5. Relativity Fundamentals for Time Scales and Astrometry . Robert A. Nelson . 2000 . USNO Sixth DoD Astrometry Forum – 5–6 December 2000 Washington, DC . http://ad.usno.navy.mil/forum/forum.html . 6 July 2012 . live . https://web.archive.org/web/20060211105847/http://ad.usno.navy.mil/forum/nelson.pdf . 11 February 2006.
  6. Naval Observatory Flagstaff Station Celebrates First Half Century . SpaceRef . 30 September 2005 . 18 October 2011.
  7. Lowell Observatory Enters the Twentieth Century – In the 1950s . Joseph S. Tenn . 2007 . Journal of Astronomical History and Heritage . 10 . 1 . 65–71 . 10.3724/SP.J.1440-2807.2007.01.06 . 2007JAHH...10...65T . 106425683 . dead . https://web.archive.org/web/20120314161802/http://www.phys-astro.sonoma.edu/people/faculty/tenn/TennLowellObsJAH2v10p65.pdf . 14 March 2012.
  8. Web site: Profiles in Science: Flagstaff has deep and broad scientific infrastructure . Arizona Daily Sun . 20 September 2014 . 6 October 2021 . 6 October 2021 . https://web.archive.org/web/20211006045748/https://azdailysun.com/news/local/profiles-in-science-flagstaff-has-deep-and-broad-scientific-infrastructure/article_faa1e84b-d037-57ba-be1b-8f06efde0c6f.html . live .
  9. Web site: Christian B. Luginbuhl's Homepage . United States Naval Observatory's Flagstaff Station . 11 April 2011 . 18 October 2011 . dead . https://web.archive.org/web/20111027221015/http://www.nofs.navy.mil/about_NOFS/staff/cbl/ . 2011-10-27.
  10. News: News Analysis: Dark skies helps seal 7-0 vote in favor of Flagstaff regional plan . Suzanne Adams-Ockrassa . Arizona Daily Sun . 2014-01-16 . 13 February 2014 . 18 January 2014 . https://web.archive.org/web/20140118005441/http://azdailysun.com/news/local/govt-and-politics/news-analysis-dark-skies-helps-seal---vote-in/article_19a371de-7e76-11e3-a0a5-001a4bcf887a.html . live .
  11. Web site: USNO Flagstaff Station Mission Statement . United States Naval Observatory's Flagstaff Station . 18 October 2011 . 19 January 2008 . https://web.archive.org/web/20080119070112/http://www.nofs.navy.mil/about_NOFS/nofs.mission.html . live .
  12. Web site: The USNO's Mission . Naval Oceanography Portal . 18 October 2011 . 27 September 2011 . https://web.archive.org/web/20110927021633/http://www.usno.navy.mil/USNO/about-us/the-usno-mission/ . live .
  13. Web site: Home . Flagstaff Dark Skies Coalition . 18 October 2011 . 5 January 2021 . https://web.archive.org/web/20210105122435/http://flagstaffdarkskies.org/ . live .
  14. News: Cyndy Cole . Flag marks 50 years of dark skies . Arizona Daily Sun . 14 April 2008 . 18 October 2011 . 26 April 2012 . https://web.archive.org/web/20120426234927/http://azdailysun.com/news/flag-marks-years-of-dark-skies/article_c8bf02f5-adbe-5be3-8c83-1c467218b49d.html . live .
  15. Web site: Home . International Dark-Sky Association . 18 October 2011 . 27 March 2011 . https://web.archive.org/web/20110327161845/http://www.darksky.org/ . live .
  16. Lighting and astronomy . Christian B. Luginbuhl . Constance E. Walker . Richard J. Wainscoat . 1 December 2009 . Physics Today . 32 . 10.1063/1.3273014 . 62 . 12 . 2009PhT....62l..32L. free .
  17. Web site: Coconino County, Arizona . Section27: Lighting . 2017-12-28 . live . https://web.archive.org/web/20171229041000/http://coconino.az.gov/documentcenter/view/388 . 2017-12-29.
  18. Web site: Flagstaff Lighting Code – Division 10-08-002 of the Land Development Code (LDC) . International Dark-Sky Association . 18 February 2016 . dead . https://web.archive.org/web/20120317142355/http://docs.darksky.org/ordinance/City-Flagstaff-AZ-Ordinance.pdf . 17 March 2012.
  19. Web site: Flagstaff Dark Skies Coalition . Chapter 10-08: Signs and Lighting . 18 February 2016 . dead . https://web.archive.org/web/20120323161924/http://www.flagstaffdarkskies.org/docs/9_%20Title10%20Chapter8%20-%20Signs%20and%20Lighting.PDF . 23 March 2012.
  20. Web site: Model Lighting Codes . Flagstaff Dark Skies Coalition . 18 October 2011 . 10 September 2011 . https://web.archive.org/web/20110910105346/http://www.flagstaffdarkskies.org/ordinances.htm . live .
  21. Book: Steven J. Dick . October 2002 . Sky and Ocean Joined – The US Naval Observatory 1830–2000 . Cambridge University Press . 978-0521815994 . 8 May 2011 . 21 October 2012 . https://web.archive.org/web/20121021151608/http://www.cambridge.org/gb/knowledge/isbn/item5708676/?site_locale=en_GB . live .
  22. Web site: Steven J. Dick . 14 April 1997 . Origins of the USNO Flagstaff Station and the 61-Inch Telescope . United States Naval Observatory's Flagstaff Station . 18 October 2011 . 28 July 2011 . https://web.archive.org/web/20110728050902/http://www.nofs.navy.mil/about_NOFS/hist.html . dead .
  23. Web site: U.S. Naval Observatory Flagstaff Telescopes . United States Naval Observatory's Flagstaff Station . 18 October 2011 . 1 November 2008 . https://web.archive.org/web/20081101035216/http://www.nofs.navy.mil/about_NOFS/telescopes/ . live .
  24. Web site: The 1.55-m Kaj Strand Astrometric Reflector . United States Naval Observatory's Flagstaff Station . 18 October 2011 . 26 July 2011 . https://web.archive.org/web/20110726143905/http://www.nofs.navy.mil/about_NOFS/telescopes/ksar.html . dead .
  25. Near-Infrared Astrometry: Progress and Prospects at USNO . Fredrick J. Vrba . Astrometry Forum . 1 March 2006 . 2017-12-29 . 4 August 2017 . https://web.archive.org/web/20170804112942/http://ad.usno.navy.mil/forum7/Talks/Session1gUNCLAS_Vrba.pdf . live .
  26. Web site: ASTROCAM: An Offner Re-imaging 1024 x 1024 InSb Camera for Near-Infrared Astrometry on the USNO 1.55-m Telescope . J. Fischer . F. Vrba . D. Toomey . R. Lucke . Shu-i Wang . A. Henden . J. Robichaud . P. Onaka . B. Hicks . F. Harris . W. Stahlberger . K. Kosakowski . C.C. Dudley . K. Johnston . Infrared – Submillimeter Astrophysics & Techniques . 18 October 2011 . https://web.archive.org/web/20111004205133/http://rsd-www.nrl.navy.mil/7213/IR/papers/Fischer-etalSPIE2003.pdf . 2011-10-04.
  27. 25th Anniversary of the Discovery of Pluto's Moon Charon . SpaceRef . 22 June 2003 . 18 October 2011.
  28. Web site: 17. Pluto, Charon & the Kuiper Belt . Laboratory for Atmospheric and Space Physics . University of Colorado . 18 October 2011 . 27 September 2011 . https://web.archive.org/web/20110927171630/http://lasp.colorado.edu/~bagenal/1010/SESSIONS/17.PlutoCharon.html . live .
  29. Web site: A Hand-Waving Derivation of Planethood . Hal Levison . Planetary Science Directorate . Southwest Research Institute, Boulder Office . 18 October 2011 . 4 August 2011 . https://web.archive.org/web/20110804223202/http://www.boulder.swri.edu/~hal/planet/index.html . live .
  30. Tytell . David . 23 July 2003 . Coolest Star Ever . Sky & Telescope . 18 October 2011 . 8 September 2012 . https://web.archive.org/web/20120908044056/http://www.skyandtelescope.com/news/3307091.html?page=1&c=y . live .
  31. Web site: The 1.3-m Reflector . United States Naval Observatory's Flagstaff Station . 18 October 2011 . 20 February 2012 . https://web.archive.org/web/20120220095831/http://www.nofs.navy.mil/about_NOFS/telescopes/13m.html . dead.
  32. Web site: wehner.org . Wehner's Photoelectric CCD . 26 January 2004 . 18 October 2011 . https://web.archive.org/web/20111026080125/http://wehner.org/electro/einstein/index.htm . 2011-10-26 . Charles Douglas Wehner.
  33. Monet, A.K.B. . Harris, F.H. . Harris, H.C. . Monet, D.G. . Stone, R.C. . First Light for USNO 1.3-meter Telescope . Bulletin of the American Astronomical Society . 33 . 1190 . November 2001 . 2001DDA....32.0404M.
  34. Improved Astrometric Calibration Regions along the Celestial Equator . Stone, Ronald C. . Pier, Jeffrey R. . Monet, David G. . The Astronomical Journal . 118 . 5 . 2488–502 . November 1999 . 10.1086/301099 . 1999AJ....118.2488S . free.
  35. Web site: Results from the Pan-STARRS Orthogonal Transfer Array (OTA) . John L. Tonry . Barry E. Burke . Sidik Isani . Peter M. Onaka . Michael J. Cooper . StarGrasp . 2013-11-14 . 24 March 2012 . https://web.archive.org/web/20120324004417/http://www.stargrasp.org/attachment/wiki/GraspPublications/spie08_ota.pdf?format=raw . live .
  36. Web site: A Tutorial on Orthogonal Arrays: Constructions, Bounds and Links to Error-correcting Codes . Douglas R. . Stinson . May 2006 . University of Waterloo . 2 December 2022 . 2 December 2022 . https://web.archive.org/web/20221202021658/https://cs.uwaterloo.ca/~dstinson/papers/caw.pdf . live .
  37. Burke, Barry E. . Tonry, John L. . Cooper, Michael J. . Young, Douglas J. . Loomis, Andrew H. . Onaka, Peter M. . Luppino, Gerard A. . Development of the orthogonal-transfer array . Blouke, Morley M. . Proceedings of the SPIE, Volume 6068 . 173–80 . February 2006 . 10.1117/12.657196 . 2006SPIE.6068..173B.
  38. Web site: MIT . Orthogonal-Transfer Arrays . Lincoln Laboratory . 18 October 2011 . 8 November 2011 . https://web.archive.org/web/20111108183729/http://www.ll.mit.edu/mission/electronics/AIT/orthogonaltransferarrays.html . live .
  39. Web site: Remote Ultra-Low Light Imaging (RULLI) . 18 February 2016 . dead . https://web.archive.org/web/20110807053514/http://pearl1.lanl.gov/external/c-cde/rulli/ . 7 August 2011.
  40. Web site: Remote Ultra Low Light-level Imaging (RULLI) (U) . National Space Security Road Map . Los Alamos National Laboratory . 18 October 2011 . https://web.archive.org/web/20121025223204/http://www.fas.org/spp/military/program/nssrm/initiatives/rullilan.htm . 2012-10-25 . 15 May 1998.
  41. Web site: Science Applications of the RULLI Camera: Photon Thrust, General Relativity and the Crab Nebula . D.G. Currie . D.C. Thompson . S.E. Buck . R.P. des Georges . Cheng Ho . D.K. Remelius . B. Shirey . T. Gabriele . V.L. Gamiz . L.J. Ulibarri . M.R. Hallada . P. Szymanski . Advanced Maui Optical and Space Surveillance Technologies (AMOS) Conference . 2013-11-14 . 3 September 2011 . https://web.archive.org/web/20110903232504/http://www.amostech.com/TechnicalPapers/2006/NROC/Currie.pdf . live .
  42. Web site: Andrea Palounek . 2009 . From Sensing to Information: Everything Under the Sun . Los Alamos National Laboratory . 2013-11-14 . 29 September 2011 . https://web.archive.org/web/20110929132350/http://faculty.physics.tamu.edu/kamon/research/talk/pac_lunch/2009/090409_Andrea_Palounek_Colloquium.pdf#25 . live .
  43. Science Results Enabled by SDSS Astrometric Observations . Ivezić . Ž. . Bond . N. . Jurić . M. . Munn . J.A. . Lupton . R.H. . Pier . J.R. . Astrometry in the Age of the Next Generation of Large Telescopes, ASP Conference Series, Vol. 338, Proceedings of a meeting held 18-20 October 2004 at Lowell Observatory, Flagstaff, Arizona, USA . P.K. . Seidelmann . A.K.B. . Monet . San Francisco . Astronomical Society of the Pacific . 2005 . 2005ASPC..338..201I . 201 . astro-ph/0701502 . 11 May 2011 . 16 January 2016 . https://web.archive.org/web/20160116221419/http://adsabs.harvard.edu/full/2005ASPC..338..201I . live .
  44. Web site: The 1.0-m Ritchey-Chretien Reflector . United States Naval Observatory's Flagstaff Station . 18 October 2011 . 28 July 2011 . https://web.archive.org/web/20110728050840/http://www.nofs.navy.mil/about_NOFS/telescopes/rc.html . dead .
  45. Web site: The 0.2-m (8-inch) FASTT . United States Naval Observatory's Flagstaff Station . 18 October 2011 . 1 November 2008 . https://web.archive.org/web/20081101052950/http://www.nofs.navy.mil/about_NOFS/telescopes/fastt.html . dead.
  46. Upgrades to the Flagstaff Astrometric Scanning Transit Telescope: A Fully Automated Telescope for Astrometry . R.C. Stone . D.G. Monet . A.K.B. Monet . F.H. Harris . H.D. Ables . C.C. Dahn . B. Canzian . H.H. Guetter . H.C. Harris . A.A. Henden . The American Astronomical Society . The Astronomical Journal . 126 . 4 . 2060–80 . 2003 . 10.1086/377622 . 2003AJ....126.2060S . 36903369 . free.
  47. Web site: The Planetary and Lunar Ephemeris DE 421 . 15 August 2009 . William M. Folkner . James G. Williams . Dale H. Boggs . Jet Propulsion Laboratory . 2013-11-14 . 16 June 2013 . https://web.archive.org/web/20130616021216/http://tmo.jpl.nasa.gov/progress_report/42-178/178C.pdf . live .
  48. NOFS Contributes to SOFIA's Observation of Challenging Pluto Occultation . 23 June 2011 . 7 May 2012 . dead . https://web.archive.org/web/20120916002229/http://www.usno.navy.mil/USNO/tours-events/NOFS_SOFIA_Release_110711.pdf . 16 September 2012.
  49. Web site: Home Page . Navy Prototype Optical Interferometer . 2013-11-14 . 15 December 2009 . https://web.archive.org/web/20091215082656/http://www.lowell.edu/npoi/index.php . dead.
  50. BAAS . 215 . 441.12 . Winter 2010 . The Science with four 1.8-m Telescopes at the Navy Prototype Optical Interferometer . P.D. Shankland . D.J. Hutter . M.E. DiVittorio . J.A. Benson . R.T. Zavala1 . K.J. Johnston . 18 February 2016 . dead . https://web.archive.org/web/20120222023621/http://ad.usno.navy.mil/edboard/090925.pdf . 22 February 2012 . 2010AAS...21544112S.
  51. Annu. Rev. Astron. Astrophys. . 2001 . 39 . 353–401 . Optical Interferometry . Andreas Quirrenbach . Annual Reviews . 2013-11-14 . dead . https://web.archive.org/web/20120323170107/http://frank.harvard.edu/~howard/papers/optical_interferometry_review.pdf . 2012-03-23 . 10.1146/annurev.astro.39.1.353 . 2001ARA&A..39..353Q.
  52. Hutter, D.J. . Benson, J.A. . DiVittorio, M. . Shankland, P.D. . Zavala, R.T. . Johnston, K.J. . Large-Angle Astrometry at the Navy Prototype Optical Interferometer (NPOI) . Bulletin of the American Astronomical Society . 41 . 675 . May 2009 . American Astronomical Society . 2009AAS...21441102H.
  53. Web site: Staff Publications . 18 February 2016 . dead . https://web.archive.org/web/20140808061310/http://www.lowell.edu/npoi/publications/bibliography.php . 8 August 2014.
  54. Web site: A Survey of Geosynchronous Satellite Glints . F.J. Vrba . M.E. DiVittorio . R.B. Hindsley . H.R. Schmitt . J.T. Armstrong . P.D. Shankland . D.J. Hutter . J.A. Benson . Advanced Maui Optical and Space Surveillance Technologies (AMOS) Conference . 2013-11-14 . 3 September 2011 . https://web.archive.org/web/20110903232748/http://www.amostech.com/TechnicalPapers/2009/Non-resolved_Object_Characterizaion/Vrba.pdf . live .
  55. Web site: Satellite Imaging and Characterization with Optical Interferometry . A.M. Jorgensen . E.J. Bakker . G.C. Loos . D. Westpfahl . J.T. Armstrong . R.L. Hindsley . H.R. Schmitt . S.R. Restaino . Advanced Maui Optical and Space Surveillance Technologies (AMOS) Conference . 2013-11-14 . 3 September 2011 . https://web.archive.org/web/20110903232833/http://www.amostech.com/TechnicalPapers/2010/Systems/Jorgensen.pdf . live .

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "United States Naval Observatory Flagstaff Station".

Except where otherwise indicated, Everything.Explained.Today is © Copyright 2009-2024, A B Cryer, All Rights Reserved. Cookie policy.