Verhoest, Niko E. C.Lievens, HansWagner, WolfgangÁlvarez-Mozos, JesúsMoran, M. SusanMattia, Francesco2014-05-292014-05-2920081424-822074110.3390/s8074213https://academica-e.unavarra.es/handle/2454/10665Synthetic Aperture Radar has shown its large potential for retrieving soil moisture maps at regional scales. However, since the backscattered signal is determined by several surface characteristics, the retrieval of soil moisture is an ill-posed problem when using single configuration imagery. Unless accurate surface roughness parameter values are available, retrieving soil moisture from radar backscatter usually provides inaccurate estimates. The characterization of soil roughness is not fully understood, and a large range of roughness parameter values can be obtained for the same surface when different measurement methodologies are used. In this paper, a literature review is made that summarizes the problems encountered when parameterizing soil roughness as well as the reported impact of the errors made on the retrieved soil moisture. A number of suggestions were made for resolving issues in roughness parameterization and studying the impact of these roughness problems on the soil moisture retrieval accuracy and scale.application/pdfeng© 2008 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland. This article is an open-access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/3.0/).Soil roughnessSoil moisture retrievalSynthetic aperture radarUncertaintyIntegral equation modelMicrowave backscatter dependenceA priori informationSar dataC bandPolarimetric sarAgriculturalFieldsProfile meterLaser scannerWet soilinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/openAccess