Ocean Inherent Optical Property Estimation from Irradiances
Abstract
A method is evaluated for estimating the absorption coefficient a and the backscattering coefficient beta(sub beta) from measurements of the upward and downward irradiances Epsilon sub mu(z) and Epsilon sub d(z). With this method, the reflectance ratio R(z) and the downward diffuse attenuation coefficient Kappa sub d(z) obtained from Epsilon sub mu(z) and Epsilon sub d(z) are used to estimate the inherent optical properties R(sub infinity) and Kappa (sub infinity) that are the asymptotic values of R(sub infinity) and Kappa (sub infinity), respectively. For an assumed scattering phase function Beta, there are unique correlations between the values of R(sub infinity) and Kappa(infinity) and those of alpha and beta(sub beta) that can be derived from the radiative transfer equation. Good estimates of alpha and the Gordon parameter G = beta(sub beta)/(alpha + beta (sub beta)) can be obtained from R(infinity) and Kappa(sub infinity) if the true scattering phase function is not greatly different from the assumed function. The method works best in deep, homogeneous waters, but can be applied to some cases of stratified waters. To improve performance in shallow waters where bottom effects are important, the deep- and shallowmeasurement reflectance models also are developed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 20, 1997
- Accession Number
- ADA464572
Entities
People
- Norman J. Mccormick
- Robert A. Leathers
Organizations
- University of Washington