Analysis of the MESSENGER MASCS photometric targets part I: Photometric standardization for examining spectral variability across mercury's surface

Examination of the Mercury Atmosphere and Surface Composition Spectrometer (MASCS) photometry sequence data sets, and comparison of modeling results using both the Hapke and Kaasalainen-Shkuratov models show that these models can provide an improved photometric standardization to the MASCS's Visible and InfraRed Spectrograph (VIRS) data sets over the current empirical correction. Properties of the MASCS photometric data set are less constraining of the Hapke model, producing more than one mathematically viable solution set of parameters. The Kaasalainen-Shkuratov model, while simpler, produces a single mathematically viable solution set to the global MASCS photometric data set, and was selected by the MASCS instrument team to provide an updated photometric standardization for the team's final delivery to the Planetary Data System archive.