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Radio and optical interferometric imagingSince diffraction-limited imaging with a single aperture yields angular resolution approx. lambda/D, the attainment of high angular resolution with single apertures requires the construction of correspondingly large monolithic apertures, the whole surface of which must be figured to much less than a wavelength. At the longer wavelengths, it is impossible to build a sufficiently large single aperture: for example, at lambda 21 cm, arcsec resolution requires an aperture of diameter approx. 50 km. At the shorter wavelengths, the atmosphere imposes a natural limit in resolution of about one arcsec. However, another route is possible; that is, using synthetic apertures to image the sky. Synthetic apertures are now in use in many fields, e.g., radio interferometry, radar imaging, and magnetic-resonance imaging. Radio-interferometric techniques developed in radio astronomy over the past 40 years are now being applied to optical and IR astronomical imaging by a number of groups. Furthermore, the problem of figuring synthetic apertures is considerably simpler, and can be implemented in a computer: new 'self-calibration' techniques allow imaging even in the presence of phase errors due to the atmosphere.
Document ID
19930004392
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Cornwell, Tim J.
(National Radio Astronomy Observatory Socorro, NM, United States)
Date Acquired
September 6, 2013
Publication Date
November 1, 1992
Publication Information
Publication: New Mexico Univ., A Lunar Optical-Ultraviolet-Infrared Synthesis Array (LOUISA)
Subject Category
Astronomy
Accession Number
93N13580
Funding Number(s)
CONTRACT_GRANT: NSF AST-88-14515
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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