Verification of the bulk method for calculating overwater optical turbulence

Abstract

A two-week overwater experiment has been performed to verify the bulk aerodynamic method for calculating the index of refraction structure function parameter, CN. Meteorological data were obtained on shipboard adjacent to a 13-km optical path over Monterey Bay. Model CQ and measured CN values agree to within 33% on the average when there is spatial homogeneity. During periods of strong sea-surface temperature gradients, disagreements by a factor of 10 are common.

Humidity's influence on visible region refractive index structure parameter C_n^2

“…[7][8][9] In those works, the wavelengths of the optical measurements were in the mid-infrared (3 to 5 m), and all showed that humidity along the measurement volume plays a significant role in the temporal behavior of C n 2 .…”

Scintillation measurements over False Bay, South Africa

“…TARMOS provides a parameterization for the marine atmospheric surface layer on the basis of standard meteorological input parameters using the well-known Monin-Obukhov similarity theory 9 . TARMOS offers two modes: with an assumed relation for z 0m , the roughness length for momentum 10 , or with an assumed relation for C DN , the drag coefficient under neutral conditions 11 . The output of TARMOS consists of the (logarithmic) vertical profiles of wind speed, temperature and water vapor, as well as characteristic turbulence (micrometeorological) quantities.…”

Effects of atmospheric refraction and turbulence on long-range IR imaging in the marine surface layer: comparisons between experiment and simulation

“…[14][15][16][17][18][19][20][21][22] Scintillation is caused by the randomly variable, normally distributed, real part of the propagation constant σ χ . The Rytov approximation predicts the following relation between σ χ and the structure function parameter for the refractive index C n 2 over a non-homogeneous path R:…”