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Proceedings Paper

Smithsonian Submillimeter Wavelength Array
Author(s): James M. Moran; Paul T. P. Ho
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Paper Abstract

The SAO Submillimeter Wavelength Array is under construction and is expected to be ready for observations in late 1997. It will consist of six telescopes with baselines from 9 to 470 m and resolutions as fine as 0.'1. Eight receivers will cover all bands from 180 to 900 GHz in linear polarization; two orthogonal polarizations will be available at 350 GHz. Multiyear site testing on Mauna Kea shows that the precipitable water vapor is less than 1 mm for 17% of the total time, and the rms phase fluctuations on a baseline of 100 m are less than 55micrometers for 25% of the total time. The configuration of the array will be optimized to provide nearly uniform coverage in the uv plane within a circular boundary for an instantaneous observation of a source at the zenith. To achieve this distribution, the antennas will be placed along the sides of Reuleaux triangles. The basic electronic architecture follows conventional practice in radio interferometry and involves heterodyne frequency conversion. The correlator-spectrometer will have 92000 spectral channels (6144 lags per baseline) and will be able to provide 1.6-MHz resolution for a total bandwidth of 4 GHz. There were several significant design changes in the past year: a sixth mirror was added to the optical path in each antenna; the antenna configuration was changed to four tangential rings rather than four concentric rings; the correlator rings; the correlator clock rate was increased from 40 to 52 MHz and the IF conversion scheme was changed from a single-sideband conversion to two conventional mixer conversions, in order to improve the image rejection.

Paper Details

Date Published: 9 June 1994
PDF: 12 pages
Proc. SPIE 2200, Amplitude and Intensity Spatial Interferometry II, (9 June 1994); doi: 10.1117/12.177251
Show Author Affiliations
James M. Moran, Harvard-Smithsonian Ctr. for Astrophysics (United States)
Paul T. P. Ho, Harvard-Smithsonian Ctr. for Astrophysics (United States)

Published in SPIE Proceedings Vol. 2200:
Amplitude and Intensity Spatial Interferometry II
James B. Breckinridge, Editor(s)

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