Computing diffuse reflection from particulate planetary surface with a new function.
Abstract
An equation is derived to compute the amount of diffuse light reflected by a particulate surface, such as on Mars or an asteroid. The method traces the paths of rays within an ensemble of randomly shaped grains and finds the eventual probability of emission. The amount of diffuse, unpolarized emitted light is obtained in terms of the real index of refraction, the imaginary index, and the average diameter of particles making up the surface. The equation is used to compute the empirical rule for obtaining the planetary albedo from the slope of its polarization curve. Accuracy of the equation, estimated at + or  4%, seems justified because of quantitative agreement with experimental measures of the empirical rule. It is also shown that the equation can be applied to bubbleenclosing surfaces such as volcanic foams. Results for the indices of the moon, Mars, Io, and Europa are obtained and compared with other data.
 Publication:

Applied Optics
 Pub Date:
 July 1981
 DOI:
 10.1364/AO.20.002493
 Bibcode:
 1981ApOpt..20.2493W
 Keywords:

 Diffuse Radiation;
 Geometrical Optics;
 Optical Transfer Function;
 Planetary Surfaces;
 Reflectance;
 Albedo;
 Error Analysis;
 Europe;
 Io;
 Lunar Surface;
 Mars Surface;
 Optical Paths;
 Particle Size Distribution;
 Polarized Light;
 Ray Tracing;
 Refractivity;
 Lunar and Planetary Exploration;
 Planetary Surfaces:Scattering