Lunar and Planetary Science XXXVII (2006) 1480.pdf SPECTROPHOTOMETRIC MODELING OF SOILS AND ROCKS AT THE OPPORTUNITY LANDING SITE. J.R. Johnson1, R.E. Arvidson2, J.F. Bell III3, R. Deen4, W. Farrand5, W. Grundy6, E. Guinness2, M. Johnson3, K.E. Herkenhoff1, M. Lemmon7, F. Seelos IV8, J. Soderblom3, S. Squyres3, and the Athena Science Team, 1U.S. Geological Survey, 2255 N. Gemini Dr., Flagstaff, AZ 86001,
[email protected], 2Washington University, St. Louis, MO, 3Cornell University, Ithaca, NY, 4Jet Propulsion Laboratory, Pasadena, CA, 5Space Sciences Institute, Boulder, CO, 6Lowell Observatory, Flagstaff, AZ, 7Texas A&M University, College Station, TX, 8Applied Physics Laboratory, Laurel, MD. Introduction: The Panoramic Camera (Pancam) on incorporating local facet tilts for ROIs. Hapke the Opportunity Mars Exploration Rovers [1] models were run using Henyey-Greenstein (HG) acquired multispectral reflectance observations of phase functions to determine the asymmetry outcrop rocks and spherule-rich soils at different parameter (ξ) for a 1-term HG, and the b (asymmetry incidence, emission, and phase angles (0-155°) that parameter) and c (backscattering fraction) parameters were used for photometric modeling to constrain the for a 2-term HG. All models included the single albedo and physical properties of the surface scattering albedo (w) and macroscopic roughness materials. Nominal filters covered wavelengths of parameter (θ ). For data sets lacking observations at 432 nm, 601 nm, 753 nm, and 1003 nm, with a stereo phase angles < 20° the opposition effect width (h) filter selected as either 436 nm or 754 nm. and amplitude (B0) were set to zero. A reduced chi- Observations.