Abstract

Monte Carlo simulation is used to evaluate the reliability of backscattering calculated from remotely sensed reflectance following the equations of Zaneveld (1989). The required optical properties include upwelling nadir radiance, downwelling scalar irradiance, and the hydrosol absorption. By assuming that "shape factors" were close to unity, Zaneveld concluded that the backscattering coefficient could be calculated to within ±30%. The shape factors for Zaneveld's model relate the volume scattering function and the radiance distribution to more routinely measured quantities. This hypothesis is examined over a variety of oceanic environments with chlorophyll concentrations ranging from 0.1 mg m^-3 to 1.0 m m^-3 and with quartz concentrations derived from Mullenberg for Sargasso Sea. For comparison, a "blue water model" simulation containing molecular water absorption and scattering from quartz and molecular water is included. The simulations are carried out for a flat ocean surface with homogeneous inherent optical properties. Preliminary results support Zaneveld's original conclusion that the backscattering estimates error by about 30%. There is a trend for the backscattering coefficient calculated with Zaneveld's equations to overestimate the actual backscattering coefficient. Backscattering coefficients calculated employing the Preisendorfer/Mobley model, and the backscattering calculated from Morel and Gordon are also presented for comparison.

© 1991 Optical Society of America