Some Brightness Variations in the North Sky and the Horizon Sky and Sea Measured During Daylight Hours
Abstract
Curves are presented to show measured diurnal variations in the luminance of the north sky at an arbitrary fixed point and also diurnal luminances, including their horizontal and vertical polarization components, of the sky and sea at the horizon. In both sets of measurements sky luminance data were obtained continuously with photoelectric photometers and recording equipment. Sky and sea luminances and their polarized components were measured manually at 15-min intervals. Large, rapid variations in the luminance of the north sky were observed because of cloud activity. At the horizon this was not observed for the sky. The effects of the sun's glitter pattern on the sea are shown; the ratio of polarization components and ratios of sky to sea values are given. The data indicate a need in visibility studies for measuring polarization characteristics and for continuously monitoring the background whether it be a point in the sky or the sky-sea horizon.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1971
- Accession Number
- AD0727118
Entities
People
- Elsie F. Dupre
- Gordon L. Stamm
Organizations
- United States Naval Research Laboratory