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On the sources of astrometric anomalous refraction


Please use this identifier to cite or link to this item: http://hdl.handle.net/1928/9828

On the sources of astrometric anomalous refraction

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Title: On the sources of astrometric anomalous refraction
Author: Taylor, Malinda Suzanne, 1979-
Advisor(s): McGraw, John T.
Committee Member(s): Pier, Jeff
Loomba, Dinesh
Rand, Rich
Department: University of New Mexico. Dept. of Physics & Astronomy
Subject: Astrometry
Anomalous Refraction
LC Subject(s): Refraction, Astronomical.
Boundary layer (Meteorology)
Degree Level: Doctoral
Abstract: Over a century ago, astronomers using transit telescopes to determine precise stellar positions were hampered by an unexplained periodic shifting of the stars they were observing. With the advent of CCD transit telescopes in the past three decades, this unexplained motion, now known as “anomalous refraction,” is again being observed. Anomalous refraction is described as a low frequency, large angular scale motion of the entire image plane with respect to the celestial coordinate system as observed and defined by previous astrometric catalogs. These motions of typically several tenths of an arcsecond with timescales on the order of ten minutes are ubiquitous to drift-scan groundbased astrometric measurements regardless of location or telescopes used and have been attributed to the effect of tilting of equal-density layers of the atmosphere. The cause of this tilting has often been attributed to atmospheric gravity waves, but never confirmed. Although theoretical models of atmospheric refraction show that atmospheric gravity waves are a plausible cause of anomalous refraction, an observational campaign specifically directed at defining this relationship provides clear evidence that anomalous refraction is not consistent with the passage of atmospheric gravity waves. The source of anomalous refraction is found to be meter scale slowly evolving coherent dynamical structures in the boundary-layer below 60 meters.
Graduation Date: July 2009
URI: http://hdl.handle.net/1928/9828

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Files Size Format View Description
MSTaylor_physics_dissertation.pdf 3.909Mb PDF View/Open Dissertation
run4203_resid_movie.wmv 3.458Mb Unknown View/Open SDSS focal plane map movie
run4203_meansubtracted_resid.wmv 3.787Mb Unknown View/Open SDSS focal plane distortion movie
FOVtilt5646.wmv 2.194Mb Unknown View/Open SDSS focal plane tilt movie

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