A Methodology for Measuring Atmospheric Downwelling Path Radiance

This report describes a methodology for measuring atmospheric downwelling path radiance (DPR). The DPR is a combination of solar scattering and emission and absorption from aerosols and gaseous molecules in the atmosphere. These processes that create DPR are briefly described, as is the instrument used to measure DPR. Measured infrared spectral DPR data are presented and compared to modeled DPR data. The measured and modeled DPR data are shown to be in good agreement, which provides confidence in the validity of the measured DPR data.