Abstract

Through Monte Carlo simulation the variation of the diffuse reflectance of natural waters with sun angle is found to be dependent on the shape of the volume scattering function (VSF) of the medium. It is demonstrated that single scattering theory can be used to estimate the reflectance—sun angle variation given the VSF, and conversely, the VSF can be retrieved from measurements of the variation of the reflectance with sun angle. Furthermore, it is shown that the complexity introduced when the illumination incident on the surface is not in the form of a simple collimated beam, e.g., by the presence of sky light and/or surface roughness, can be described by a single parameter, which can be determined from incident radiance distribution and wind speed: the downwelling distribution function in the absence of scattering.

© 1989 Optical Society of America