Application of multiple photometric models to disk-resolved measurements of Mercury’s surface: Insights into Mercury’s regolith characteristics

Abstract

a b s t r a c tPhotometric analyses are used to standardize images obtained at a variety of illumination and viewing conditions to a common geometry for the construction of maps or mosaics and for comparison with spectral measurements acquired in the laboratory. Many models exist that can be used to model photometric behavior. Two of the most commonly use models, those of Hapke and Kaasalainen-Shkuratov, are compared for their ability to standardize MESSENGER images of Mercury. Analysis of the modeling results shows that photometric corrections using the Kaasalainen-Shkuratov model provides significantly less contrast between images acquired at large differences in emission angle. The contrast seen between images acquired at large differences in either incidence and phase angle is smaller with the Hapke model based corrections, but not significantly better than that provided by the Kaasalainen-Shkuratov model. Photometric studies are also used to infer scattering properties of the surface regolith. The quantitative correlation between photometric model parameters and surface properties is questionable, but laboratory studies do indicate general correlations and trends between parameters and sample properties that allow for comparisons between surfaces based on photometric modeling. Based on comparisons with the Moon and several asteroids that have been observed by spacecraft, the photometric analyses presented here are interpreted to indicate that Mercury's regolith is smoother on micrometer scales and has a narrower particle size distribution with a lower mean particle size than lunar regolith. Grain structures of regolith particles from Mercury are inferred to be different than those of the Moon or those asteroids observed to date. Mercury's regolith may contain a component compositionally distinct from lunar regolith.

Photometric Modeling and VIS‐IR Albedo Maps of Dione From Cassini‐VIMS

“…In this work we have adopted the method given by Shkuratov et al () to photometrically correct the Cassini‐VIMS data of Dione. A similar approach has been successfully applied to other solar system bodies, for example, Mercury (Domingue et al, ), asteroids 4 Vesta and 21 Lutetia (Longobardo et al, ), and the Earth's Moon (Kaidash et al, ).…”

“…In this work we have adopted the method given by Shkuratov et al (2011) to photometrically correct the Cassini-VIMS data of Dione. A similar approach has been successfully applied to other solar system bodies, for example, Mercury (Domingue et al, 2016), asteroids 4 Vesta and 21 Lutetia (Longobardo et al, 2016), and the Earth's Moon (Kaidash et al, 2009). For a given geometry defined by means of incidence (i), emission (e), and phase (g) angles, the radiance factor I∕F( , i, e, g) is given by the product…”

Photometrically-corrected global infrared mosaics of Enceladus: New implications for its spectral diversity and geological activity

“…Similar approach has been previously applied on the Earth's Moon (Shkuratov et al, 1999(Shkuratov et al, , 2011Kreslavsky et al, 2000), Mercury (Domingue et al, 2016), Vesta (Schröder et al, 2013;Combe et al, 2015), Ceres (Schröder et al, 2017), Tethys and Dione (Filacchione et al, 2018a,b).…”

Global Spectral Properties and Lithology of Mercury: The Example of the Shakespeare (H‐03) Quadrangle

“…We applied a Kaasalainen‐Shkuratov model (Kaasalainen et al, ; Shkuratov & Helfenstein, ) to normalize our images to the geometric conditions commonly used in laboratory experiments, that is, incidence angle i =30°, emission angle e =0°, and phase angle α = 30°. This model gives a better global photometric correction, in particular, for seams between images of different illumination conditions (Domingue et al, ), than the Hapke model (Domingue et al, ; Hapke, ; Hapke et al, ).…”