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Proceedings Paper

On the relationship between Cn2 and humidity
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Paper Abstract

We have recently shown the refractive index structure constant C2n in the visible and near infrared to be a strong function of humidity in the absence of solar insolation effects, in stark contrast to the commonly held assumption that the humidity contribution can be ignored in that waveband. We expand our analysis of the effects of humidity on C2n as measured across a 100-m long horizontal beam path to include temperature. Also we present a new technique for extracting information on changes in the parameter space of C2n and local weather variables, which we term Hilbert Phase Analysis (HPA). This methodology, based on extracting the phase of the analytic signal via Hilbert transforms, reveals a wealth of detail that conventional analysis techniques cannot determine. The HPA provides additional confirmation that C2n is strongly influenced by local humidity in the visible region. We have also found that HPA provides a clear demonstration that humidity competes with temperature in affecting the value of C2n.

Paper Details

Date Published: 12 July 2006
PDF: 12 pages
Proc. SPIE 6268, Advances in Stellar Interferometry, 62683D (12 July 2006); doi: 10.1117/12.672205
Show Author Affiliations
Carlos O. Font, Univ. of Puerto Rico (United States)
Mark P. J. L. Chang, Univ. of Puerto Rico (United States)
Erick A. Roura, Univ. of Puerto Rico (United States)
Eun Oh, U.S. Naval Research Lab. (United States)
Charmaine Gilbreath, U.S. Naval Research Lab. (United States)

Published in SPIE Proceedings Vol. 6268:
Advances in Stellar Interferometry
John D. Monnier; Markus Schöller; William C. Danchi, Editor(s)

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