Journal ArticleDOI
Measurement and behavior of dual-polarization vegetation optical depth and single scattering albedo at 1.4- and 5-GHz microwave frequencies
TLDR
In this article, a measurement procedure was developed and tested to determine horizontal and vertical polarization radiative transfer properties, i.e., single scattering albedo and optical depth, of vegetation under field conditions.Abstract:Â
A measurement procedure has been developed and tested to determine horizontal and vertical polarization radiative transfer properties, i,e., single scattering albedo (/spl omega/) and optical depth (/spl tau/), of vegetation under field conditions. The procedure was applied to a wheat crop for a series of biomass densities. The measurements were done using two different radiometers (1.4 and 5 GHz) and for different view angles. The measurements and calculations indicated that the ratios of horizontal and vertical polarization radiative transfer properties (/spl alpha/=/spl Gamma//sub h///spl Gamma//sub /spl nu//, /spl alpha/'=/spl tau//sub h///spl tau//sub /spl nu// and /spl beta/=/spl omega/h//spl omega//sub /spl nu//) are slightly dependent on view angle. However, no significant dependence on biomass density could be discerned.read more
Citations
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Journal ArticleDOI
A methodology for surface soil moisture and vegetation optical depth retrieval using the microwave polarization difference index
TL;DR: The methodology uses a radiative transfer model to solve for surface soil moisture and vegetation optical depth simultaneously using a nonlinear iterative optimization procedure and does not require any field observations of soil moisture or canopy biophysical properties for calibration purposes and may be applied to other wavelengths.
Journal ArticleDOI
Retrieving near-surface soil moisture from microwave radiometric observations: current status and future plans
Jean-Pierre Wigneron,Jean-Christophe Calvet,Thierry Pellarin,A.A. Van de Griend,M. Berger,Paolo Ferrazzoli +5 more
TL;DR: In this article, a review of surface soil moisture retrieval from microwave radiometric systems is presented, highlighting key issues that will have to be addressed in the near future to secure operational use of the proposed retrieval approaches.
Journal ArticleDOI
Two-Dimensional Microwave Interferometer Retrieval Capabilities over Land Surfaces (SMOS Mission)
TL;DR: In this article, an L-band 2-D microwave interferometric radiometer for monitoring surface variables over land surfaces is discussed. But the authors focus on the retrieval capabilities of the satellite for monitoring soil moisture, vegetation biomass, and surface temperature.
Journal ArticleDOI
The b-factor as a function of frequency and canopy type at H-polarization
TL;DR: This paper confirms that when a large frequency domain is considered, the b-factor is inversely proportional to the power of the wavelength b=c/(/spl lambda/)/sup x/, which is in line with theoretical considerations.
Journal ArticleDOI
Characterizing the dependence of vegetation model parameters on crop structure, incidence angle, and polarization at L-band
Jean-Pierre Wigneron,M. Parde,Philippe Waldteufel,Andre Chanzy,Yann Kerr,S. Schmidl,Niels Skou +6 more
TL;DR: This dependence was investigated for several crop types (corn, soybean, wheat, grass, and alfalfa) based on L-band experimental datasets and should be useful for developing more accurate forward modeling and retrieval methods over mixed pixels including a variety of vegetation types.
References
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Journal ArticleDOI
Microwave Dielectric Behavior of Wet Soil-Part II: Dielectric Mixing Models
TL;DR: In this paper, the authors evaluated the microwave dielectric behavior of soil-water mixtures as a function of water content and soil textural composition for the 1.4-to 18-GHz region.
Book
Microwave Scattering and Emission Models and their Applications
TL;DR: First-order radiative transfer solution passive sensing formulation of the surface scattering problem surface model and special cases ranges validity of the IEM model matrix doubling formulations for scattering and emission scattering and emissions models for snow and sea ice comparisons of model predictions with backscattering and emission measurements from snow and ice.
Journal ArticleDOI
Influence of land-surface evapotranspiration on the earth's climate
Jagadish Shukla,Y. Mintz +1 more
TL;DR: Calculations with a numerical model of the atmosphere show that the global fields of rainfall, temperature, and motion strongly depend on the land- surface evapotranspiration.
Journal ArticleDOI
Spatial variability of field-measured soil-water properties
TL;DR: In this article, hydraulic conductivity was measured as a function of soil-water content at 30.5 cm depth intervals to a depth of 182.9 cm in twenty 6.5 meters square plots randomly established over a 150-hectare field.