A 1-Bit Digital Autocorrelator

Abstract

In this paper, we present a 1-bit method of computing autocorrelation functions. The experimental set-up of a 40-channel 1-bit autocorrelator developed at the Physical Research Laboratory, Ahmedabad is presented. Using noise input, the correlator was tested in conjunction with the 70-MHz IF amplifier, which forms a part of an RF spectral line receiver developed for the purpose of detecting OH emissions at 18-cm wavelength from interstellar hydroxyl molecules. Two sets, one of 7 and the other of 50 minutes of integration time, of test observations were analysed to compute autocorrelation functions and power spectra. It is concluded that the highest accuracy of spectral measurements would be achieved provided the latter are made in the flat region of the response of the band-pass filter.

Additional information

Notes on contributors

S.K. Alurkar

Alurkar, S K (Dr): Dr. S.K. Alurkar is Associate Professor working as Principal Investigator of Interplanetary Scintillation Project in the Solar and Planetary Physics Area of the Physical Research Laboratory, Ahmedabad. He did his MSc in 1956 from the Poona University and joined PRL as a Research Scholar in 1957 to work under the supervision of Prof. K.R. Ramanathan. In 1965 he obtained his Ph.D. in, ionospheric physics. During 1969–72 he worked as a Post-doctoral fellow in the Institute of Space Research in Brazil. For the following few months, he was with the Department of Physics, University of Adelaide, Australia as a Visiting Fellow.

R.V. Bhonsle

Bhonsle, R V (Dr): Dr. R.V. Bhonsle is presently a Professor and Chairman in Solar and Planetary Physics Area at W the Physical Research Laboratory, Ahmedabad. After getting M.Sc. in Physics (Poona University) in 1954, he obtained Ph.D. in ionospheric physics in 1960 at PRL. From 1961 to 1963, he was a post-doctoral fellow of the W National Research Council of Canada where he studied polarization characteristics of solar radio bursts. From 1963 to 1966, he was a Visiting Research Associate at the Radio Science Laboratory, Stanford University (USA), where he carried out satellite studies of the ionosphere. His present fields of interest are solar radio astronomy, and the interplanetary medium.