Model of Disk-Averaged Moon Polarization

Abstract

The Moon can be used as a stable calibration target for on-orbit satellite instruments without the need for solar diffusers or atmospheric correction. Radiometric models of the Moon have been developed to enable lunar calibration; however, to the authors’ knowledge, a polarization model of the Moon to improve lunar calibration of polarization-sensitive instruments has not been published. In this work, models of the disk-averaged degree of linear polarization (DoLP) in terms of lunar geometry variables were developed for nine spectral bands (336, 365, 383, 450, 519, 650, 800, 900 nm, and a broadband channel with a response from 400 to 1000 nm) using measurements from three previously published datasets. The set of models was named the Lunar disk-Averaged Model of Polarization (LAMP). LAMP includes two types of models: a model dependent on phase angle and Sun selenographic longitude was used for all nine channels, and a second model incorporating libration variables (observer selenographic latitude and longitude) was used for the three channels with the most observations. The majority of the residuals for the simpler model of DoLP were within 0.01, and the majority for the model with libration dependence were within 0.005 (for measured DoLP values ranging from −0.016 to 0.204).