Error in radar-derived soil moisture due to roughness parameterization: an analysis based on synthetical surface profiles

In the past decades, many studies on soil moisture retrieval from SAR demonstrated a poor correlation between the top layer soil moisture content and observed backscatter coefficients, which mainly has been attributed to difficulties involved in the parameterization of surface roughness. The present...

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Detalles Bibliográficos
Autores: Lievens, Hans, Vernieuwe, Hilde, Álvarez-Mozos, Jesús, Baets, Bernard de, Verhoest, Niko E. C.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2009
País:España
Institución:Universidad Pública de Navarra
Repositorio:Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
OAI Identifier:oai:academica-e.unavarra.es:2454/10726
Acceso en línea:https://hdl.handle.net/2454/10726
Access Level:acceso abierto
Palabra clave:SAR
Soil moisture
Soil roughness parameterization
Microwave dielectric behavior
Aperture radar
Bare soils
Multi incidence
Wet soils
Data
Retrieval
Models
Backscattering
Scattering
Chemistry
Electrochemistry
Descripción
Sumario:In the past decades, many studies on soil moisture retrieval from SAR demonstrated a poor correlation between the top layer soil moisture content and observed backscatter coefficients, which mainly has been attributed to difficulties involved in the parameterization of surface roughness. The present paper describes a theoretical study, performed on synthetical surface profiles, which investigates how errors on roughness parameters are introduced by standard measurement techniques, and how they will propagate through the commonly used Integral Equation Model (IEM) into a corresponding soil moisture retrieval error for some of the currently most used SAR configurations. Key aspects influencing the error on the roughness parameterization and consequently on soil moisture retrieval are: the length of the surface profile, the number of profile measurements, the horizontal and vertical accuracy of profile measurements and the removal of trends along profiles. Moreover, it is found that soil moisture retrieval with C-band configuration generally is less sensitive to inaccuracies in roughness parameterization than retrieval with L-band configuration.