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Analysis of an infrared mirage sequence.

Authors
Type
Published Article
Journal
Applied optics
Publication Date
Volume
36
Issue
21
Pages
5217–5223
Identifiers
PMID: 18259336
Source
Medline
License
Unknown

Abstract

Infrared observations of seaborne thermal sources are subject to the effects of atmospheric refraction. For low elevation angles at long ranges, out to the limit of visibility, the inevitable atmospheric temperature gradients frequently produce mirages. I present an analysis of a 22-min sequence of images recorded on 18 February 1994 at the U.S. Naval Surface Warfare Center at Wallops Island, Virginia. The infrared target is a heat source carried on a ship moving in a straight line toward the camera. The images show a quasi-periodic variation of the horizon elevation, as well as an extended range of visibility. A model that reasonably reproduces the observed features consists of a small temperature inversion in a slightly sloped atmosphere, with an atmospheric gravity wave moving across the line of sight.

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