title: Techniques for measuring radiance in sea and air.
abstract: Measurements of scattered sunlight often employ simple radiometers that are incapable of scanning azimuth phi and zenith angle theta. Instead, they measure integral moments of the radiance. Consider a set of N + 1 meters designed to measure moments Lambda(l) through Lambda(N+1). If each meter is judiciously designed, the Lambda(j) may be processed quite simply to deduce inherent properties of the scattering medium, namely, N moments of the volume scattering function. In the optimum design, each meter has an angular response that approximates a polynomial of degree N in cos theta. The theory of these meters is based on Boltzmann's equation of radiative transfer expressed in terms of spherical harmonics, a form in which this equation is particularly simple.
authors.affiliation: Tetra Tech, Inc., 630 N. Rosemead Boulevard, Pasadena, California 91107, USA.
authors.forename: W H
authors.initials: WH
authors.lastname: Wells