The performances of Electro-Optical (EO) systems such as visible or infrared cameras, lasers, operating within the Marine Surface Boundary Layer (MSBL), i.e. at heights up to a few tens of meters above the sea surface, are disturbed by various propagation mechanisms: molecular attenuation, aerosol extinction, refraction and turbulence. Refraction is responsible for focusing and defocusing of rays, detection range limitations, mirage formation and angular deviation. These refraction phenomena can be efficiently described using ray-tracing in conjunction with bulk estimations of the refractivity profiles based on the Monin-Obukhov (MO) theory. For stable atmospheric conditions (i.e. air temperature greater than sea temperature), the accuracy of the model predictions has been strongly discussed in the recent years. By using measurements of apparent target elevations recorded during the VAMPIRA trial, this paper aims at clarifying this discussion.

Date Published: 29 October 2007
PDF: 10 pages
Proc. SPIE 6747, Optics in Atmospheric Propagation and Adaptive Systems X, 674704 (29 October 2007); doi: 10.1117/12.737080

Published in SPIE Proceedings Vol. 6747:
Optics in Atmospheric Propagation and Adaptive Systems X
Karin Stein; Anton Kohnle; John D. Gonglewski, Editor(s)