Atmospheric limitations on speckle astrometry with large telescopes

Richard G. Dekany, Matt Cheselka, E. K. Hege, J. Roger P. Angel, James W. Beletic

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Scopus citations


Traditional differential astrometric techniques are limited in precision by the atmosphere in a way that does not show much improvement with increased telescope aperture. However, greatly improved astrometric precision may be obtainable by exploiting the strong aperture dependence of the spatial correlation between simultaneously recorded specklegrams within the speckle isoplanatic angle. The cross-correlation of two speckle images of a binary star pair may yield higher astrometric precision in the measurement of the binary separation than centroid differences. The degree of this improvement, however, depends strongly upon the effective thickness of the turbulence in the atmosphere. A 5- minute observation using a large-format, rapid-readout CCD at a 2.3-m telescope has demonstrated 1-milliarcsec precision in the determination of the separation of a 7.3 arcsec binary star pair when processed with speckle techniques.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
EditorsJames B. Breckinridge
PublisherPubl by Society of Photo-Optical Instrumentation Engineers
Number of pages11
ISBN (Print)0819414956
StatePublished - 1994
EventAmplitude and Intensity Spatial Interferometry II - Kailua, HI, USA
Duration: Mar 15 1994Mar 16 1994

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


OtherAmplitude and Intensity Spatial Interferometry II
CityKailua, HI, USA

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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