NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Multifrequency microwave radiometer measurements of soil moistureGround-based microwave radiometer experiments are carried out to investigate the effects of moisture, temperature, and roughness on microwave emission from bare soils. The measurements are made at frequencies of 0.6-0.9, 1.4, and 10.7 GHz using van-mounted radiometers to observe prepared soil sites in Kern County, CA. Brightness temperature variations of approximately 15 K at 1.4 GHz and 25 K at 10.7 GHz are observed as a result of diurnal changes in the soil temperature. Increasing the soil moisture content from 2% to 15% by volume is found to result in brightness temperature decreases of approximately 70 K at 0.775 and 1.4 GHz and 40 K at 10.7 GHz, depending, to a lesser extent, on polarization and viewing angle. The results attest the significance of soil temperature in deriving soil moisture from microwave radiometer measurements. Comparisons of the microwave measurements with theoretical predictions using smooth surface models give reasonable agreement and support previous results of this nature obtained with other soil types.
Document ID
19830033637
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Njoku, E. G.
(California Institute of Technology, Jet Propulsion Laboratory, Pasadena CA, United States)
Oneill, P. E.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
August 11, 2013
Publication Date
October 1, 1982
Publication Information
Publication: IEEE Transactions on Geoscience and Remote Sensing
Volume: GE-20
Subject Category
Earth Resources And Remote Sensing
Accession Number
83A14855
Funding Number(s)
CONTRACT_GRANT: NAS7-100
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available