Progress on the Big Optical Array (BOA)

J. Thomas Armstrong

doi:10.1117/12.177283

9 June 1994 Progress on the Big Optical Array (BOA)

J. Thomas Armstrong

Proceedings Volume 2200, Amplitude and Intensity Spatial Interferometry II; (1994) https://doi.org/10.1117/12.177283
Event: 1994 Symposium on Astronomical Telescopes and Instrumentation for the 21st Century, 1994, Kailua, Kona, HI, United States

Abstract

The Navy Prototype Optical Interferometer (NPOI) is nearing the completion of the first phase of construction at the Lowell Observatory on Anderson Mesa, AZ. The NPOI comprises two sub- arrays, the Big Optical Array (BOA) and the USNO Astrometric Interferometer (AI), which share delay lines, the optics laboratory, the control system, and parts of the feed optics. We describe the design of and progress on the BOA, the imaging component of the NPOI. The AI is described elsewhere (Hutter, these proceedings). As of the date of this symposium, most of the civil engineering is complete, including the control and laboratory buildings and the concrete piers for the initial array. Three AI siderostats and associated feed pipes, three delay lines, the initial three-way beam combiner, and much of the control system are in place. First fringes are anticipated in April. By the end of 1994, four AI and two BOA siderostats, as well as three more delay lines, will be installed, making imaging with all six siderostats possible. The complete BOA will consist of six 50 cm siderostats and 30 siderostat stations in a Y with 251 m arms, with baseline lengths from 4 m to 437 m. Nearly redundant baseline lengths will allow fringe tracking on long baselines on which the visibilities are too low for detection in real time. A six-way beam combiner (Mozurkewich, these proceedings) will allow simultaneous measurements of 15 visibilities and nine of 10 independent closure phases. The output beams will feed 32-channel spectrometers covering the range from 450 to 900 nm. We anticipate tracking fringes on stars brighter than 10^m, imaging surfaces of stars brighter than 4^m, measuring stellar diameters to 0.18 milliarcsec (mas), and measuring binary orbits with major axes as small as 0.4 mas.

Citation Download Citation

J. Thomas Armstrong "Progress on the Big Optical Array (BOA)", Proc. SPIE 2200, Amplitude and Intensity Spatial Interferometry II, (9 June 1994); https://doi.org/10.1117/12.177283

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available