Solar radiation at radio frequencies and its relation to sunspots.
TLDR
Experimental studies of solar radiation on a frequency of 200 Mcyc/sec are described in this article, which has characteristics similar to those of thermal radiation but is always hundreds of times greater than the thermal radiation anticipated from the photosphere and sometimes greater by a factor of 104.Abstract:
Experimental studies of solar radiation on a frequency of 200 Mcyc./sec. are described. This radiation has characteristics similar to those of thermal radiation but is always hundreds of times greater than the thermal radiation anticipated from the photosphere and sometimes greater by a factor of 104.read more
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Journal ArticleDOI
A New type of interferometer for use in radio astronomy
R. Hanbury Brown,R. Q. Twiss +1 more
Abstract: Summary A new type of interferometer for measuring the diameter of discrete radio sources is described and its mathematical theory is given. The principle of the instrument is based upon the correlation between the rectified outputs of two independent receivers at each end of a baseline, and it is shown that the cross-correlation coefficient between these outputs is proportional to the square of the amplitude of the Fourier transform of the intensity distribution across the source. The analysis shows that it should be possible to operate the new instrument with extremely long baselines and that it should be almost unaffected by ionospheric irregularities.
Journal ArticleDOI
The Navy Prototype Optical Interferometer
J. T. Armstrong,J. T. Armstrong,David Mozurkewich,Lee J. Rickard,Donald J. Hutter,James A. Benson,P. F. Bowers,N. M. Elias,Christian A. Hummel,K. J. Johnston,David F. Buscher,David F. Buscher,James H. Clark,Long Ha,L.-C. Ling,N. M. White,Richard S. Simon,Richard S. Simon +17 more
TL;DR: The NPOI as mentioned in this paper is a joint project of the Naval Research Laboratory (NRL) and the US Naval Observatory (USNO) in cooperation with the Lowell Observatory (LO).
Book ChapterDOI
A New Radio Interferometer and Its Application to the Observation of Weak Radio Stars
TL;DR: In this article, a new type of radio interferometer has been developed which enables the radiation from a weak point source such as a radio star to be recorded independently of the radiation of much greater intensity from an extended source.
Journal ArticleDOI
Introduction to Radio Astronomy
TL;DR: A general description of the nature of radio astronomy, its differences from optical astronomy, a review of the earliest beginnings of galactic and solar radio astronomy and a listing of other important observational discoveries is given in this paper.
Journal ArticleDOI
The 74 MHz System on the Very Large Array
Namir E. Kassim,T. Joseph W. Lazio,W. C. Erickson,Richard A. Perley,W. D. Cotton,Eric W. Greisen,A. S. Cohen,Brian C. Hicks,Henrique R. Schmitt,Debora M. Katz +9 more
TL;DR: In this paper, the authors present an example of a wide-field image, devoid of bright objects and containing hundreds of weaker sources, constructed from the field-based calibration and imaging.
References
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Journal ArticleDOI
Solar Radiations in the 4-6 Metre Radio Wave-Length Band
TL;DR: In this paper, it was revealed that during the War, Army equipments observed solar radiations of the order of 105 times the power expected from the sun, assuming that the sun behaves as a perfect black-body radiator at a temperature of 6,000° K.
Journal ArticleDOI
Radio-Frequency Energy from the Sun
TL;DR: Radio-FREQUENCY radiation in the ten-metre range of wave-lengths which appeared to originate in the region of the Milky Way was reported by Jansky in 1933 and it was deduced that this ‘cosmic static’ originated in interstellar space.
Journal ArticleDOI
Departure of Long-Wave Solar Radiation from Black-Body Intensity
TL;DR: In this article, it was found that the intensity of solar radiation approximately conformed to that emitted by a black body at a temperature of 6,000° K. In another series of experiments of somewhat allied character, Jansky is reported to have been unable to detect solar radiation using a longer wave-length, of 14·6 metres, although his apparatus was sufficiently sensitive to detect the electromagnetic radiation, which he discovered in 1931, coming from the vicinity of the Milky Way.