Accession Number:

AD0743931

Title:

Incident and Reflected Solar Radiation in a Tropical Environment.

Descriptive Note:

Final rept. 1 Feb 70-31 Jan 72,

Corporate Author:

CARIBBEAN RESEARCH INST ST THOMAS VI

Personal Author(s):

• Adams, John B.
• Larsen, Jean D.
• Bond, Richard M.

Report Date:

1972-02-01

Pagination or Media Count:

92.0

Abstract:

Field measurements were made of incident and reflected radiation on the island of St. Croix, U.S. Virgin Islands lat. 17 degrees 45 min. N. Climatic zones of St. Croix range from desert to tropical rain forest. Field measurements were supplemented by laboratory data and by aerial photography. Spectral reflectance measurements were made of the major types of rocks, soils and vegetation. The main rock types are readily identified by their reflectance properties, whereas the soils are less distinctive. Trees and other plants are difficult to identify by optical properties alone. Enhanced irradiation is common at certain solar angles from orographically controlled cumulus streets and from the sea surface. Radiation under a tropical forest canopy assumes the spectral distribution of chlorophyll. Visible wavelengths are strongly attenuated and near-infrared radiation may be dominant. Author

Descriptors:

• *TROPICAL REGIONS
• MULTIBAND SPECTRAL RECONNAISSANCE
• SOLAR RADIATION
• SOILS
• PLANTS(BOTANY)
• VIRGIN ISLANDS
• CLOUDS

Subject Categories:

• Infrared Detection and Detectors
• Military Intelligence

Distribution Statement:

APPROVED FOR PUBLIC RELEASE