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Proceedings Paper

Digital spectrometers for the Nobeyama 45-m telescope
Author(s): Kazuo Sorai; Kazuyoshi Sunada; Sachiko Kawabe Okumura; Iwasa Tetsuro; Atsushi Tanaka; Kazuhito Natori; Hirofumi Onuki
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Paper Abstract

New digital spectrometers for the 25-BEam Array Receiver System (BEARS) of the Nobeyama 45-m telescope are described. A commercial digital oscilloscope is used as a digitizer. The digitizer samples analogue data with 2 bits (4 levels). Data of 512 MHz bandwidth are processed for four beams at the same time. The data-formatting unit demultiplexes 2 bits 8 data in parallel to 32 parallels and sends outputs to LSIs. General purpose LSIs for autocorrelation read the digital data with a clock rate of 32 MHz. Thirty-two LSIs of 32 lags connected in cascades calculate 1024-lag autocorrelation, and output a 1024-channel power spectrum of 512 MHz bandwidth. The bandwidth of 32 MHz is achieved by picking up the data in a rate of 1/16 in the front part of the autocorrelator module. The total performances have been demonstrated by long-term integration of noise signals from receivers and observations of the Galactic star-forming region W51 in CO line.

Paper Details

Date Published: 3 July 2000
PDF: 10 pages
Proc. SPIE 4015, Radio Telescopes, (3 July 2000); doi: 10.1117/12.390466
Show Author Affiliations
Kazuo Sorai, Nobeyama Radio Observatory (Japan)
Kazuyoshi Sunada, Nobeyama Radio Observatory (Japan)
Sachiko Kawabe Okumura, Nobeyama Radio Observatory (Japan)
Iwasa Tetsuro, Sony/Tektronix Co. (Japan)
Atsushi Tanaka, Tokyo Electron Ltd. (Japan)
Kazuhito Natori, Oki Electric Industry Co. Ltd. (Japan)
Hirofumi Onuki, Oki Electric Industry Co. Ltd. (Japan)

Published in SPIE Proceedings Vol. 4015:
Radio Telescopes
Harvey R. Butcher, Editor(s)

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