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Effects of varying soil moisture contents and vegetation canopies on microwave emissionsResults of NASA airborne passive microwave scans of bare and vegetated fields for comparison with ground truth tests are discussed and a model for atmospheric scattering of radiation by vegetation is detailed. On-board radiometers obtained data at 21, 2.8, and 1.67 cm during three passes over each of 46 fields, 28 of which were bare and the others having wheat or alfalfa. Ground-based sampling included moisture in five layers down to 15 cm in addition to soil temperature. The relationships among the brightness temperature and soil moisture, as well as the surface roughness and the vegetation canopy were examined. A model was developed for the dielectric coefficient and volume scattering for a vegetation medium. L- to C-band data were found useful for retrieving soil information directly. A surface moisture content of 5-35% yielded an emissivity of 0.9-0.7. The data agreed well with a combined multilayer radiative transfer model with simple roughness correction.
Document ID
19820055671
Document Type
Reprint (Version printed in journal)
Authors
Burke, H.-H. K. (MIT, Lincoln Laboratory, Lexington MA, United States)
Schmugge, T. J. (NASA Goddard Space Flight Center Hydrospheric Sciences Branch, Greenbelt, MD, United States)
Date Acquired
August 10, 2013
Publication Date
July 1, 1982
Subject Category
EARTH RESOURCES AND REMOTE SENSING
Funding Number(s)
CONTRACT_GRANT: NAS5-25529
Distribution Limits
Public
Copyright
Other