The isoplanatic patch is defined as an arbitrary area of the sky over which the path length of incoming electromagnetic waves (such as light or radio waves) only varies by a relatively small amount relative to their wavelength.[1] Typically this area is measured by angular size. Poor seeing or a larger telescope aperture will decrease the size of a patch. Thus, the patch size varies inversely with the Fried parameter and the telescope's angular resolution. In order to correct for atmospheric distortion, telescopes fitted with adaptive optics use a bright light source such as a laser to identify the properties of a patch in the area of interest.

See also

References

  1. ↑ Thompson, A. Richard; Moran, James M.; Swenson, Jr., George W. (November 20, 2008), Interferometry and Synthesis in Radio Astronomy, Wiley, p. 640, ISBN 9783527617852.

Further reading

  • Birney S, Gonzalez G, Oesper D "observational astronomy" second edition, Cambridge university press, 2006


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