Accession Number : ADA135843

Title :   The Relation between Isolated Tree Brightness Temperature and Grass Background Brightness Temperature,


Personal Author(s) : Krusinger,A E

PDF Url : ADA135843

Report Date : Aug 1983

Pagination or Media Count : 37

Abstract : This study involves thermal infrared measurement for the determination of the diurnal and seasonal aspects of the relations between isolated evergreen tress and a cut grass background and between a large truck brightness temperature and cut grass, uncut grass, and bare soil backgrounds. Seasonal changes in the tree brightness temperature-background brightness temperature contrast ranged from 4 to 5 C in February and March to 1 to 2 C in July. At night, the thermal contrast between trees and background was found to vary inversely with long wave incoming radiation, which is a measure of cloudiness. A study of the change in the thermal contrast during the night showed that, during clear weather, the contrast was at a peak a few hours after sundown and decreased the rest of the night. In overcast conditions, a reduced contrast peak occurred at sundown and very gradually diminished through the night. Isothermal conditions were found to occur in the early mornings, and the time of these occurrences changed seasonally, in a systematic manner. (Author)

Descriptors :   *Radiometry, *Infrared radiation, Background radiation, Trucks, Trees, Infrared images, Contrast, Grasses, Diurnal variations, Seasonal variations, Brightness, Soils, Temperature, Peak values, Thermal targets, Cloud cover, Airborne, Infrared scanning

Subject Categories : Infrared Detection and Detectors

Distribution Statement : APPROVED FOR PUBLIC RELEASE