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Norman J McCormick

Publications and source records attributed to Norman J McCormick.

2 recordsLinked to original sources

Ocean optics estimation for absorption, backscattering, and phase function parameters.

We propose and test an inverse ocean optics procedure with numerically simulated data for the determination of inherent optical properties using in-water radiance measurements. If data are available at only one depth within a deep homogeneous water layer, then the single-scattering albedo and the single parameter that characterizes the Henyey-Greenstein phase function can be estimated. If data are available at two depths, then these two parameters can be determined along with the optical thickness so that the absorption and scattering coefficients, and also the backscattering coefficient, can be estimated. With a knowledge of these parameters, the albedo and Lambertian fraction of reflected radiance of the bottom can be determined if measurements are made close to the bottom. A simplified method for determining the optical properties of the water also is developed for only three irradiance-type measurements if the radiance is approximately in the asymptotic regime.

Journal Article↗

Analytic beam spread function for ocean optics applications.

A discrete ordinates code is developed with which to compute the beam spread function (BSF) without invoking the small-angle scattering approximation or performing Monte Carlo calculations. The computed BSF is used to predict the response of a detector versus its distance to the origin of a highly collimated beam, its angle with respect to the beam, and the two local angles that specify the detector orientation. Numerical results have been obtained for water models that simulate a clear ocean, a coastal ocean, and a turbid harbor. Six orders of magnitude or more change in the detector response caused by scattered photons can be predicted for different detector locations while simultaneously obtaining small changes for different detector orientations. This capability is useful for assessment of the sensitivity of the detector response to the interpretation of time-independent underwater imaging systems or visibility models.

Journal Article↗