DIRECT AND INDIRECT VISIBLE RADIATION YIELD FROM A POINT SOURCE UNDER DIFFERENT WEATHER CONDITIONS
ARMY SIGNAL RESEARCH AND DEVELOPMENT LAB FORT MONMOUTH NJ
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Measurements of ratios of scattered to direct thermal radiation in the visible region were made on 17 nights during the period from October 1960 to February 1961, at Oakhurst, New Jersey, between two and three miles west of the ocean shoreline. Source-to-receiver distances of approximately one and two miles were involved, with general weather conditions varying from close to two miles visibility, snow-covered ground, and overcast skies, to clear skies, no snow, and visibility greater than 20 miles. Results indicate situations where the indirect or scattered radiation is appreciably greater than the direct radiation. Tentative empirical relationships are derived for a l8O deg receiver field of view in a hazy atmosphere for some of the cases where no snow and cloudless skies exist, and compared with those of several previous investigators in the field. Results are also presented for cases involving snow-covered ground and or clouds. An empirical relationship is tentatively developed for the situation involving only the presence of snow. In addition, some consideration is given to the multiple scattering problem.
- Atmospheric Physics