Parameters of the positive polarization maximum of the Moon: Mapping

The distributions of the positive polarization degree maximum P _max and, for the first time, of its phase angle _max were mapped (for wavelengths _eff = 461 nm and 669 nm) on the basis of polarimetric CCD observations of the eastern hemisphere of the Moon. The distributions of the spectropolarimetric index for the positive polarization degree maximum CP _max=P _max(669 nm)/P _max(461 nm) and of the color of the maximum polarization angle C_max=_max (669 nm)/ _max (461 nm) were mapped as well. It has been found that (i) the dependences of _max on the logarithm of albedo and on the logarithm of P _maxare linearly correlated to a large degree; (ii) the parameters _max and P _maxdepend on wavelength only due to albedo variations; (iii) there are two branches in the spectropolarimetric index CP_max-albedo correlation diagram: mare regions show anti-correlation, and highlands, correlation. The maps obtained in this study can be useful both for developing remote sensing methods for the Moon and other atmosphereless bodies and for testing models of positive polarization of the light reflected by regolith-like surfaces.Translated from Astronomicheskii Vestnik, Vol. 39, No. 1, 2005, pp. 51–60.Original Russian Text Copyright © 2005 by Korokhin, Velikodsky.