LABORATORY SIMULATION OF LIGHT SCATTERING FROM REGOLITH ANALOGUES: EFFECT OF POROSITY

Title & Authors
LABORATORY SIMULATION OF LIGHT SCATTERING FROM REGOLITH ANALOGUES: EFFECT OF POROSITY
KAR, AMRITAKSHA; DEB, SANJIB; SEN, A.K.; GUPTA, RANJAN;

Abstract
The surfaces of most atmosphereless solar system objects are referred to as regolith, layers of loosely connected fragmentary debris, produced by meteorite impacts. Measurements of light scattered from such surfaces provides information about the composition and structure of the surface. A suitable way to characterize the scattering properties is to consider how the intensity and polarization of scattered light depends on the particle size, composition, porosity, roughness, wavelength of incident light and the geometry of observation. In the present work, the effect of porosity on bidirectional reflectance as a function of phase angle is studied for alumina powder with grain size of $\small{0.3{\mu}m}$ and olivine powder with grain size of $\small{49{\mu}m}$ at 543.5 nm. The optical constants of the alumina sample for each porosity were calculated with Maxwell Garnett effective medium theory. On using each of the optical constants of alumina sample in Mie theory with the Hapke model the variation of bidirectional reflectance is obtained as a function of phase angle with porosity as a parameter. Experimental reflectance data are in good agreement the model. For the olivine sample the effect of porosity is studied using Hapke (2008).
Keywords
bidirectional reflectance: EMT;porosity;regolith;scattering;
Language
English
Cited by
References
1.
Deb, D., Sen, A. K., Das, H. S., & Gupta, 2011, The Photometric Study of Light Scattering from the Surface of Alumina Powder and Interpretations by Hapke Formula, Advances in Space Research, 48, 1274

2.
Hapke, B., 1993, Theory of Reflectance and Emittance Spectroscopy, Cambridge University Press, New York, NY

3.
Hapke, B., 2008, Bidirectional Reflectance Spectroscopy. 6. Effects of Porosity, Icarus, 195, 918-926

4.
Maxewell Garnett, J. C., Phil. Trans. R. Soc. Lond., 203(1904), 835

5.
Sakai, T. & Nakamura, A. M., 2005, Quantification of Porosity and Surface Roughness in Laboratory Measurements of the Bidirectional Reflectance of Asteroid Surface Ana-logues, EPS, 57, 71-76