Accession Number : ADA311591

Title :   Effects of Atmospheric Refraction on Long-Range, Near-Surface, Electro-Optical Sensing Over Water.

Descriptive Note : Final rept. May 94-Nov 95,

Corporate Author : INSTITUTE FOR DEFENSE ANALYSES ALEXANDRIA VA

Personal Author(s) : Bauer, Ernest

PDF Url : ADA311591

Report Date : JAN 1996

Pagination or Media Count : 26

Abstract : Modern electro-optical sensors are much more sensitive than the human eye, so-other things being equal-they can detect a target much farther away than a human observer can. However, such sensors look through a long optical path in the atmosphere and at such distances atmospheric refraction effects can affect sensor viewing. This paper begins with a review of variations in the normal atmospheric temperature profile in the lowest 50-100 m above the surface the 'Atmospheric Surface Layer' (ASL)-pointing out that the horizontal range for target detection can vary, possibly by more than a factor of two. The perception of multiple targets produced by a variety of optical mirage phenomena is also discussed. The purpose of this discussion is to point out new meteorological concepts (developed, largely in the context of air pollution meteorology, in the 1960's) to the electro-optical propagation, and to raise some questions as to the operational significance of refraction that produces multiple images, which the author cannot yet answer.

Descriptors :   *ELECTROOPTICS, *OPTICAL DETECTORS, *ATMOSPHERIC REFRACTION, AIR POLLUTION, ATMOSPHERIC TEMPERATURE, PATHS, MULTIPLE TARGETS, BOUNDARY LAYER, OPTICAL IMAGES, PROFILES, LONG RANGE(DISTANCE), METEOROLOGY, VISUAL PERCEPTION, TARGET DETECTION, RANGE(DISTANCE).

Subject Categories : Optical Detection and Detectors
      Atmospheric Physics
      Electrooptical and Optoelectronic Devices

Distribution Statement : APPROVED FOR PUBLIC RELEASE