Visible-NIR imaging polarimetry of painted metal surfaces viewed under a variably cloudy atmosphere

摘要

An imaging spectro-polarimeter was used to measure polarization signatures in five visible and near infrared channels (450, 490, 530, 630, 700 nm) from four painted steel plates throughout the day as the solar angle and sky conditions changed. The primary objective of this study was to characterize the influence of variable sky conditions on the observed polarization signatures. Smooth plates exhibited higher degree of polarization than rough plates and black plates generally exhibited higher degree of polarization than tan plates. Changes in cloudiness caused large variations in the polarization, usually reducing the observed degree of polarization.