Download or read book U S Naval Observatory Optical Interferometer Project AZ CA written by and published by . This book was released on 1992 with total page 530 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Navy Prototype Optical Interferometer written by John Thomas Armstrong and published by . This book was released on 1998 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: We describe the Navy Prototype Optical Interferometer (NPOI), a joint project of the Naval Research Laboratory (NRL) and the US Naval Observatory (USNO) in cooperation with Lowell Observatory. The NPOI has recently begun operations at the Lowell Observatory site near Flagstaff, Arizona, obtaining its first images, of a binary star, in 1996 May and June and its first limb-darkening observations during 1996 November to 1997 February. This paper gives an overview of the NPOI, including the characteristics of optical interferometry that affect its design. The NPOI includes subarrays for imaging and for astrometry. The imaging subarray consists of six moveable 50 cm siderostats feeding 12 cm apertures, with baseline lengths from 2.0 to 437 m. The astrometric subarray consists of four fixed 50 cm siderostats feeding 12 cm apertures (35 cm apertures to be installed in 1998), with baseline lengths from 19 m to 38 m. The shared back end covers 450-850 nm in 32 channels. The NPOI features vacuum feed and delay systems, active group-delay fringe tracking, and a high degree of automation. The astrometric subarray also includes an extensive site laser metrology system to measure the motions of the siderostats with respect to one another and to the bedrock. For imaging stellar surfaces, arrays with equal spacing between elements are superior to arrays that have been laid out to optimize (u, v) coverage and that therefore have unequal spacing. The imaging subarray of the NPOI provides a number of equally spaced configurations with linear scales at ratios of 1.64. Unequally spaced configurations are available for a variety of other imaging programs. Coherence across either type of imaging configuration is maintained by phase bootstrapping: the phases on the longest baselines, on which fringes may be too weak to track, are stabilized by tracking fringes on the shortest baselines.
Download or read book Description of the U S Naval Observatory Astrometric Interferometer written by and published by . This book was released on 1990 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Phase 1 Construction of the Navy Prototype Optical Interferometer written by and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This final technical report for contract N00014-91-C-2224 summarizes all work accomplished in the construction of the Navy Prototype Optical Interferometer (NPOI), Phase I. Reference is made to all environmental reports and permits, construction of roads, buildings, array piers, and power distribution. Quarterly reports, summary budget, job descriptions of personnel, and publications are included.
Download or read book United States Naval Observatory Astrometric Interferometer written by Donald John Hutter and published by . This book was released on 1994 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The U.S. Naval Observatory Astrometric Interferometer (AI) is the dedicated astrometric subarray of the new Navy Prototype Optical Interferometer (NPOI) at Lowell Observatory, which is being built in collaboration with the Naval Research Laboratory. The Naval Research Laboratory is constructing the imaging subarray of the NPOI, the 'Big Optical Array' (BOA). The AI will be in operation on Anderson Mesa, near Flagstaff, Arizona, in the spring of 1994. The AI was built using the experience gained from the Mark III Interferometer on Mt. Wilson, CA, which demonstrated 'proof of concept' of wide-angle astrometry by a long baseline optical interferometer. The AI incorporates four siderostats that are located in a Y-shaped configuration, and features a full-array laser metrology system to monitor baseline motion. The AI shares with the BOA state-of-the-art delay lines and a real-time zero- order fringe tracking system. The AI will have a limiting magnitude of 10 and will produce star positions accurate to a few milliarcseconds (mas). With a planned operational lifetime of several decades, this instrument will be capable of maintaining the HIPPARCOS reference frame through repeated observations, yielding improved proper motions of thousands of the brighter HIPPARCOS stars.
Download or read book Federal Register written by and published by . This book was released on 1992-08-20 with total page 990 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Very High Angular Resolution Imaging written by J.G. Robertson and published by Springer Science & Business Media. This book was released on 2013-12-01 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 1990s are proving to be a very exciting p&iod for high angular resolution astronomy. At radio wavelengths a combination of new array instruments and pow erful imaging algorithms have generated images of unprecedented resolution and quality. In the optical and infrared, the great technical difficulties associated with constructing separated-aperture interferometers have been largely overcome, and many new instruments are now operating or are being developed. As these pro grams start to produce observational results they will be able to draw extensively on the experience gained by the radio-interferometry community. Thus it seemed that the time was ripe for a meeting which would bring together workers from all wavelength ranges to discuss the details of the science and art of "Very High Angular Resolution Imaging" . While the main emphasis of Symposium No. 158 was on high resolution tech niques from the radio, mm-wave, infrared and optical bands, it also provided an opportunity for presentation of astronomical results from these techniques. As well as giving our colleagues from the Northern Hemisphere a break from midwinter, the location of the Symposium in Australia recognised the continuing development of astronomical interferometry in this country, especially the recent completion of the Australia Telescope radio array, and the progress toward com missioning of the Sydney University Stellar Interferometer. A number of the par ticipants visited these instruments during the post-symposium tour.
Download or read book The Outrigger Telescopes Project Mauna Kea Science Reserve written by and published by . This book was released on 2005 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Role of VLBI in Astrophysics Astrometry and Geodesy written by Franco Mantovani and published by Springer Science & Business Media. This book was released on 2004-06-22 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: A masterly survey of the last 13 years of Very Long Baseline Interferometry, reviewed in light of the most advanced astronomical observations. Topics covered include: Nonthermal emission from extragalactic radio sources; Principles of synchrotron emission in relation to astrophysics; Theory of relativistic jets; Young, powerful radio sources and their evolution; Scintillation in extragalactic radio sources; Radio and optical interferometry; Radio polarimetry; Unified schemes; Deep fields; Tropospheric and ionospheric phase calibration; Supernovae; VLBI for geodesy and geodynamics.
Download or read book OYSTER written by Christian Hummel and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Navy Prototype Optical Interferometer Recent Developments Since 2004 written by and published by . This book was released on 2006 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: The technical status of the Navy Prototype Optical Interferometer (NPOI) since the last SPIE meeting is summarized along with the current science programs. The instrument is operated in an automatic observational mode, obtaining over 10,000 stellar observations in the period, June 2004 through March 2006. The scientific program has been directed at astrometry, TPF candidate stars, binary stars and other interesting targets such as Be stars. A significant database of NPOI observations obtained in 1997-2004 is being analyzed for binaries and single stars such as rapid rotating stars: Altair and Vega.
Download or read book Astronomy with Optical Interferometers written by and published by . This book was released on 1990 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book United States Naval Observatory written by United States Naval Observatory and published by . This book was released on 1993 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Astronomical Applications of Astrometry written by M. A. C. Perryman and published by Cambridge University Press. This book was released on 2009 with total page 695 pages. Available in PDF, EPUB and Kindle. Book excerpt: An authoritative account of the contributions to science made by the Hipparcos satellite, for astronomers, astrophysicists and cosmologists.
Download or read book Publications of the United States Naval Observatory written by United States Naval Observatory and published by . This book was released on 1906 with total page 626 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reprint written by United States Naval Observatory and published by . This book was released on 1970 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Introduction to Optical Stellar Interferometry written by A. Labeyrie and published by Cambridge University Press. This book was released on 2006-06-29 with total page 295 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the last two decades, optical stellar interferometry has become an important tool in astronomical investigations requiring spatial resolution well beyond that of traditional telescopes. This book, first published in 2006, was the first to be written on the subject. The authors provide an extended introduction discussing basic physical and atmospheric optics, which establishes the framework necessary to present the ideas and practice of interferometry as applied to the astronomical scene. They follow with an overview of historical, operational and planned interferometric observatories, and a selection of important astrophysical discoveries made with them. Finally, they present some as-yet untested ideas for instruments both on the ground and in space which may allow us to image details of planetary systems beyond our own.
