Point Target Extinction and Scintillation as function of range at LAPTEX, Crete
conference paper
The range performance of IRST sensors is partly determined by the propagation of the atmosphere. For low altitude targets the boundary layer of the atmosphere introduces a variety of effects due to inhomogeneities, for which model predictions are not yet well validated. For this reason NATO Research Study Group 5 on "Maritime Infrared Target and Background Signatures, Measurement and Characterization" organized the Low Altitude Point Target EXperiment (LAPTEX) in the Mediterranean Sea at the NATO-FORACS site at Crete (Greece) from 8-26 July 1996. In this experiment a wide beam point source was mounted on a small ship, sailing out and in along a straight line to the detecting sensors. The same ship was equipped with a comprehensive set of meteorological instrumentation. By determination of the signal decrease with range, propagation models such as LOWTRAN7 can be validated. This concerns the transmission, assuming that the source radiant intensity is known. Of similar importance is the increase of scintillation with range, predicted by other models. In this paper the setup of the LAPTEX trial is described and the results of some examples of the extinction and scintillation experiments are presented. It is concluded that for the subtropical conditions like at Crete, the LOWTRAN extinction predictions correspond surprisingly well with the measurements. The agreement between the predicted and measured scintillation appears to be less good. ©2005 Copyright SPIE - The International Society for Optical Engineering.
Topics
TNO Identifier
95006
Publisher
SPIE
Source title
Proceedings SPIE - Propagation and Imaging through the Atmosphere, 29-31 July 1997, San Diego, CA
Editor(s)
Bissonnette, L.R.
Dainty, C.
Dainty, C.
Place of publication
Bellingham, WA.
Pages
167-179