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Estimation of Bare Surface Soil Moisture and Surface Roughness Parameter Using L-Band SAR Image DataAn algorithm based on a fit of the single-scattering Integral Equation Method (IEM) was developed to provide estimation of soil moisture and surface roughness parameter (a combination of rms roughness height and surface power spectrum) from quad-polarized synthetic aperture radar (SAR) measurements. This algorithm was applied to a series of measurements acquired at L-band (1.25 GHz) from both AIRSAR (Airborne Synthetic Aperture Radar operated by the Jet Propulsion Laboratory) and SIR-C (Spaceborne Imaging Radar-C) over a well- managed watershed in southwest Oklahoma. Prior to its application for soil moisture inversion, a good agreement was found between the single-scattering IEM simulations and the L band measurements of SIR-C and AIRSAR over a wide range of soil moisture and surface roughness conditions. The sensitivity of soil moisture variation to the co-polarized signals were then examined under the consideration of the calibration accuracy of various components of SAR measurements. It was found that the two co-polarized backscattering coefficients and their combinations would provide the best input to the algorithm for estimation of soil moisture and roughness parameter. Application of the inversion algorithm to the co-polarized measurements of both AIRSAR and SIR-C resulted in estimated values of soil moisture and roughness parameter for bare and short-vegetated fields that compared favorably with those sampled on the ground. The root-mean-square (rms) errors of the comparison were found to be 3.4% and 1.9 dB for soil moisture and surface roughness parameter, respectively.
Document ID
20000038178
Acquisition Source
Goddard Space Flight Center
Document Type
Reprint (Version printed in journal)
Authors
Shi, Jian-Cheng
(California Univ. Santa Barbara, CA United States)
Wang, James
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Hsu, Ann Y.
(NASA Goddard Space Flight Center Greenbelt, MD United States)
ONeill, Peggy E.
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Engman, Edwin T.
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Date Acquired
August 19, 2013
Publication Date
January 1, 1997
Publication Information
Publication: Laboratory for Hydrospheric Processes Research Publications
ISSN: 0196-2892
Subject Category
Earth Resources And Remote Sensing
Distribution Limits
Public
Copyright
Other

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