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Targeted and all-sky search for nanosecond optical pulses at Harvard-Smithsonian

Horowitz, Paul and Coldwell, Charles and Howard, Andrew and Latham, David and Stefanik, Robert and Wolff, Jonathan and Zajac, Joe (2001) Targeted and all-sky search for nanosecond optical pulses at Harvard-Smithsonian. In: The Search for Extraterrestrial Intelligence (SETI) in the Optical Spectrum III. Proceedings of SPIE. No.4273. Society of Photo-Optical Instrumentation Engineers , Bellingham, WA, pp. 119-127. ISBN 9780819439512.

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We have built a system to detect nanosecond pulsed optical signals from a target list of some 10,000 sun-like stars, and have made some 20,000 observations during its two years of operation. A beamsplitter feeds a pair of hybrid avalanche photodetectors at the focal plane of the 1.5m Cassegrain at the Harvard/Smithsonian Oak Ridge Observatory (Agassiz Station), with a coincidence triggering measurement of pulse width and intensity at sub-nanosecond resolution. A flexible web-enabled database, combined with mercifully low background coincidence rates (approximately 1 event per night), makes it easy to sort through far-flung data in search of repeated events from any candidate star. An identical system will soon begin observations, synchronized with ours, at the 0.9m Cassegrain at Princeton University. These will permit unambiguous identification of even a solitary pulse. We are planning an all-sky search for optical pulses, using a dedicated 1.8m f/2.4 spherical glass light bucket and an array of pixelated photomultipliers deployed in a pair of matched focal planes. The sky pixels, 1.5 arcmin square, tessellate a 1.6 by 0.2 degree patch of sky in transit mode, covering the Northern sky in approximately 150 clear nights. Fast custom IC electronics will monitor corresponding pixels for coincident optical pulses of nanosecond timescale, triggering storage of a digitized waveform of the light flash.

Item Type:Book Section
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URLURL TypeDescription
Howard, Andrew0000-0001-8638-0320
Latham, David0000-0001-9911-7388
Additional Information:© 2001 SPIE. We gratefully acknowledge the enlightened and continued support of The Planetary Society (TPS) and the Bosack- Kruger Charitable Foundation, and additional support from the SETI Institute. David Brown’s matching contribution to TPS made possible the all-sky project. We thank Nathan Hazen and James Oliver for designing the “Garage-Mahal” observatory building. We are indebted to the night observers at Agassiz Station for their tireless efforts that bring us so many photons.
Funding AgencyGrant Number
The Planetary Society (TPS)UNSPECIFIED
Bosack-Kruger Charitable FoundationUNSPECIFIED
Subject Keywords:Optical SETI, interstellar communication
Series Name:Proceedings of SPIE
Issue or Number:4273
Record Number:CaltechAUTHORS:20170705-130843401
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Official Citation:Paul Horowitz ; Charles M. Coldwell ; Andrew B. Howard ; David W. Latham ; Robert Stefanik ; Jonathan Wolff ; Joe M. Zajac; Targeted and all-sky search for nanosecond optical pulses at Harvard-Smithsonian. Proc. SPIE 4273, The Search for Extraterrestrial Intelligence (SETI) in the Optical Spectrum III, 119 (August 3, 2001); doi:10.1117/12.435364
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:78768
Deposited By: Tony Diaz
Deposited On:05 Jul 2017 22:30
Last Modified:15 Nov 2021 17:42

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