Time smearing

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Under time smearing (engl., Ger., Temporal blurring ') refers to a deterioration of the reconstructed image astronomical object equipped with a ground-based interferometer was observed, which occurs due to the duration of observation. In contrast to individual telescopes or cameras, which can compensate the earth's rotation in real time with a special mount , the various telescopes of the interferometer are located at fixed positions on the earth. As a result, maps made with interferometers have the elongated orthoradial features that are similar to those of night sky photographs taken with a fixed tripod. The blurring is a problem with long integration times or with widely separated telescopes. Mostly a problem in radio astronomy , it severely limits the usable field of view of observations in Very Long Baseline Interferometry .

literature

  • Alan H. Bridle, Frederic R. Schwab: Wide Field Imaging I: Bandwidth and Time-Average Smearing in Synthesis imaging in radio astronomy 1989. In: Richard A. Perley, Frederic R. Schwab (eds.): Synthesis imaging in radio astronomy , A collection of Lectures from the Third NRAO Synthesis Imaging Summer School Volume 6, Astronomical Society of the Pacific, San Francisco, CA, ISBN 0-937707-23-6 , p. 247, bibcode : 1989ASPC .... 6..247B .