POLLEX Trial Report: A Study of Turbulence in the Littoral Zone


  1. Forand, J.L.
  2. Potvin, G.
  3. Dion, D.
Corporate Authors
Defence R&D Canada - Valcartier, Valcartier QUE (CAN)
The POLLEX trial was carried out to study the effects of refraction and turbulence on atmospheric propagation and their impact on optical imaging systems, in particular Infrared Search and Track systems (IRSTs). During earlier NATO trials (MAPTIP and LAPTEX) the data collected on point target signatures showed quantitative scintillation effects when the optical paths propagated through the lowest regions of the marine boundary layer. Similar effects have also been observed during other measurement campaigns; however, a consistent problem has always been the determination or measurement of the refractive index structure function coefficient, Cn², upon which all turbulence calculations depend. The group’s need for additional data sets obtained under stable atmospheric conditions, when the air-sea temperature difference (ASTD) is positive and over-the-horizon detection is possible, was also a driving force for this trial. TG16 chose to perform the trials in Livorno during the month of May because of the high probability of the occurrence of stable atmospheric conditions in the spring. With a water temperature of 17°C and an offshore wind, air temperatures of up to 22°C and higher were expected. In addition, Mariteleradar (MTR), the Italian Defence Research Institute, agreed to host the trial, offered secure locations for the group’s measurement equipment, the use of the ship, Porpora, to install an instrumented buoy and perform runs with calibrated IR sources a

Il y a un résumé en français ici.

IRST (Infrared Search and Track);Optical propagation;Surface layer turbulence;maritime surface layer;imaging
Report Number
DRDC-VALCARTIER-TR-2004-452 — Technical Report
Date of publication
01 Apr 2006
Number of Pages

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