Survey of emissivity variability in thermography of urban areas

Journal Article · Wed Sep 01 00:00:00 EDT 1982 · Remote Sensing Environ.; (United States)

DOI:https://doi.org/10.1016/0034-4257(82)90043-8· OSTI ID:6428251

Artis, D A; Carnahan, W H

This study investigates the effects of roof emissivity variation of aerial thermogram images. Thermograms have been used to detect heat loss from residential roofs. Emissivity variation among rooftops, however, can lead to a misrepresentation of the temperatures mapped in a thermogram image. The objectives of this study were (1) to demonstrate the feasibility of a technique to use remotely sensed data to calculate surface emissivities, and (2) to use that technique to determine the extent of emissivity variation in urban surfaces. In the first part of the experimental approach a passive technique is developed to calculate emissivity from two-band thermal infrared radiance data. In the second part of the experimental approach the technique was used to measure the emissivity of 1411 roofs within the city limits of Terre Haute, Indiana. Results of this survey indicated that over 98% of the roofs surveyed were confined to a very narrow range of emissivities. It is concluded that the observed variation in rooftop emissivities has a minimal effect on the temperatures depicted in thermograms.

• Research Organization: Indiana State University, Terre Haute, IN
• OSTI ID: 6428251
• Journal Information: Remote Sensing Environ.; (United States), Vol. 12
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ROOFS
EMISSIVITY
HEAT LOSSES
THERMOGRAPHY
ERRORS
AERIAL MONITORING
BRIGHTNESS
MAPPING
MULTISPECTRAL SCANNERS
REMOTE SENSING
URBAN AREAS
ENERGY LOSSES
LOSSES
MEASURING INSTRUMENTS
MEASURING METHODS
MONITORING
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
SURFACE PROPERTIES
500400* - Environment
Atmospheric- Thermal Effluents Monitoring & Transport- (-1989)