Title:	Radio scattering and imaging
Authors:	Narayan, R. Cornwell, T.J. Goodman, Jeremy Anantharamaiah, K.R.
Keywords:	IMAGE PROCESSING RADIO ASTRONOMY RADIO SCATTERING RADIO TELESCOPES SIGNAL TO NOISE RATIOS INTERSTELLAR MATTER PLANETARY ATMOSPHERES SOLAR WIND WAVE FRONTS
Issue Date:	1990
Publisher:	Pergamon Press
Citation:	URSI/IAU Symposium on Radio Astronomical Seeing, Beijing, People's Republic of China, May 15-19, 1989, Proceedings. Beijing/Oxford, International Academic Publishers/Pergamon Press, 1990, p205-211
Abstract:	The problem of scattering-induced image distortion ('seeing') in radio astronomy is studied theoretically, emphasizing the strong scattering regimes. The thin-screen approximation is utilized, where a single effective phase-changing screen replaces the extended scattering medium. Length scales are appropriately redefined for an infinitely distant source to characterize incident radiation as plane wavefronts. Imaging regimes, including speckle, seeing disk, snapshot, average, and ensemble-average images are defined and identified for a number of astronomical scattering media. Strong scattering is shown to occur in all cases except in the troposphere, and very strong scattering is identified in the case of scattering by the interstellar medium. Source imaging of very high resolution is allowed by the snapshot regime when a fully redundant array and good signal/noise ratios within extremely short integration times are present. Examining the magnitude and spectrum of refractive-index fluctuations is facilitated by the average regime.
Description:	Restricted Access. Research supported by Alfred P. Sloan Foundation and David and Lucille Packard Foundation.
URI:	http://hdl.handle.net/2289/2634
Alternative Location:	http://adsabs.harvard.edu/cgi-bin/bib_query?1990ursi.symp..205N
Copyright:	1990 Pergamon Press
Appears in Collections:	Research Papers (A&A)

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