TY - JOUR
T1 - Martian phase function
T2 - Modeling the visible to near-infrared surface photometric function using HST-WFPC2 data
AU - Soderblom, Jason M.
AU - Bell, James F.
AU - Hubbard, Min Y.H.
AU - Wolff, Michael J.
N1 - Funding Information:
We thank the TES Team for calculating and publishing dust opacities and Eldar Noe Dobrea for his help in retrieving these data for each of our observation dates. We thank Jeffrey Johnson (USGS) and John Hillier (Grays Harbor College) for their valuable reviews of this manuscript. Funding for this research was provided by grants from the NASA Planetary Geology and Geophysics Program (NNG04G163G) and the Space Telescope Science Institute. This work is based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by Association of Universities for Research in Astronomy under NASA contract.
PY - 2006/10
Y1 - 2006/10
N2 - Images of Mars in the visible to near-infrared acquired from 1996 to 2005 using the Hubble Space Telescope WFPC2 have been used to model the martian surface photometric function at 502, 673, 953, and 1042 nm. These data range in spatial resolution from 12 to 70 km/pixel at the sub-Earth point, and in phase angle coverage from 0.34° to 40.5°. The WFPC2 images have been calibrated to radiance factor or I / F and projected to a cylindrical map for coregistration and comparison to similarly mapped spacecraft data sets of albedo, topography, thermal inertia, composition, and geology. We modeled the observed I / F as a function of phase angle using Minnaert, Lambert, lunar-Lambert, and Hapke photometric functions for numerous regions of interest binned into albedo units defined by Viking and TES albedo maps, and thermal-inertia units defined by TES thermal-inertia maps. Visibly opaque water-ice clouds and data acquired under high dust opacity conditions were excluded from the analysis. Our modeling suggests that under average to low atmospheric dust opacity conditions and over this range of phase angles, the photometric properties of the martian surface at 502, 673, 953, and 1042 nm are best modeled by lunar-Lambert functions with parameters derived for three surface units defined by low, moderate, and high TES bolometric albedos.
AB - Images of Mars in the visible to near-infrared acquired from 1996 to 2005 using the Hubble Space Telescope WFPC2 have been used to model the martian surface photometric function at 502, 673, 953, and 1042 nm. These data range in spatial resolution from 12 to 70 km/pixel at the sub-Earth point, and in phase angle coverage from 0.34° to 40.5°. The WFPC2 images have been calibrated to radiance factor or I / F and projected to a cylindrical map for coregistration and comparison to similarly mapped spacecraft data sets of albedo, topography, thermal inertia, composition, and geology. We modeled the observed I / F as a function of phase angle using Minnaert, Lambert, lunar-Lambert, and Hapke photometric functions for numerous regions of interest binned into albedo units defined by Viking and TES albedo maps, and thermal-inertia units defined by TES thermal-inertia maps. Visibly opaque water-ice clouds and data acquired under high dust opacity conditions were excluded from the analysis. Our modeling suggests that under average to low atmospheric dust opacity conditions and over this range of phase angles, the photometric properties of the martian surface at 502, 673, 953, and 1042 nm are best modeled by lunar-Lambert functions with parameters derived for three surface units defined by low, moderate, and high TES bolometric albedos.
KW - Mars
KW - Photometry
KW - Spectrophotometry
KW - surface
UR - http://www.scopus.com/inward/record.url?scp=33748677684&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33748677684&partnerID=8YFLogxK
U2 - 10.1016/j.icarus.2006.05.006
DO - 10.1016/j.icarus.2006.05.006
M3 - Article
AN - SCOPUS:33748677684
SN - 0019-1035
VL - 184
SP - 401
EP - 423
JO - Icarus
JF - Icarus
IS - 2
ER -