Polarimetric Measurements of Simulated Lunar Surfaces.

Abstract

view Abstract Citations (1) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Polarimetric Measurements of Simulated Lunar Surfaces. Egan, Walter G. ; Smith, Lewis L. Abstract Polarimetric studies of rough surfaces serve to delimit the range of their appropriate physical properties and geometries. In an effort to lay the basis for an analytical approach, the polarization properties of volcanic ash and furnace slag were investigated as a function of particle size, albedo and porosity, since current theories of polarization indicate that these properties are significant. These investigations were made on a large-scale polarimeter (4-in.-diameter viewing area) in order that coarse specimens could be analyzed. For both samples, it was found that the maximum percent polarization (positive) and the corresponding phase angle at zero and 60 deg viewing angles, the inversion angle and the minimum percent polari- zation (negative) varied as a function of porosity and albedo. It was found that the best fit to Crisium (Gehrels et al.) could be achieved with Haleakala volcanic ash with particle sizes between 37 and 88 IL' and furnace slag less than 37 IL; Clavius could be fitted with the ash of sizes less than 37 IL' and the furnace slag less than 1 IL The polarimetric properties of the furnace slag, volcanic ash, and additional laboratory samples were investigated for wavelength dependence. It was found that the best color-polarimetric and best visual photometric match to Crisium were obtained with coarse chunks of the volcanic ash topped with less than 1 IL particles of itself. This work is supported by NASA under Contract NAS 9-4942. Publication: The Astronomical Journal Pub Date: August 1966 DOI: 10.1086/109936 Bibcode: 1966AJ.....71..383E full text sources ADS |