Analysis of the Backscattering Coefficient of Salt-Affected Soils Using Modeling and RADARSAT-1 SAR Data

Salt significantly changes the backscattering coefficient of wet soil. This is easily observed on RADARSAT-1 synthetic aperture radar (SAR) images acquired over a salty depression located in the Egyptian desert. The aim of this paper is to use backscattering models to understand the behavior of the backscattering coefficient over salt-affected soils and to evaluate the possibility of monitoring the salt content. Simulations conducted over salt-affected soils show a lower sensitivity of these models to soil moisture compared to nonaffected soils. Besides, there is no model suitable to represent the variation of the backscattering coefficient due to changes in soil salinity. These results are discussed with regard to the magnitude of the two components of the dielectric constant (epsiv' and epsiv''). Based on a series of relationships, we propose a parametric formulation that allows us to determine the salinity acting on RADARSAT-1 SAR images without any use of backscattering models

[1]  Pascale C. Dubois,et al.  Measuring soil moisture with imaging radars , 1995, IEEE Trans. Geosci. Remote. Sens..

[2]  W. T. McGeorge,et al.  Diagnosis and Improvement of Saline and Alkaline Soils , 1954 .

[3]  Richard K. Moore,et al.  Radar remote sensing and surface scattering and emission theory , 1986 .

[4]  Graciela Metternicht,et al.  Spatial discrimination of salt- and sodium-affected soil surfaces , 1997 .

[5]  Graciela Metternicht,et al.  Remote sensing of soil salinity: potentials and constraints , 2003 .

[6]  Ramata Magagi,et al.  MODELLING THE BACKSCATTERING COEFFICIENT OF SALT-AFFECTED SOILS: APPLICATION TO WADI EL-NATRUN BOTTOM, EGYPT , 2004 .

[7]  F. Henderson,et al.  Principles and Applications of Imaging Radar , 1998 .

[8]  Darren Bell,et al.  The Application of Dielectric Retrieval Algorithms for Mapping Soil Salinity in a Tropical Coastal Environment Using Airborne Polarimetric SAR , 2001 .

[9]  A. Stogryn,et al.  Equations for Calculating the Dielectric Constant of Saline Water (Correspondence) , 1971 .

[10]  P. V. Narasimha Rao,et al.  Dielectric properties of salt-affected soils , 1995 .

[11]  L. A. Richards.  Diagnosis and Improvement of Saline and Alkali Soils , 1954 .

[12]  Huadong Guo,et al.  Effect of dielectric properties of moist salinized soils on backscattering coefficients extracted from RADARSAT image , 2003, IEEE Trans. Geosci. Remote. Sens..

[13]  F. Ulaby,et al.  Microwave Dielectric Behavior of Wet Soil-Part II: Dielectric Mixing Models , 1985, IEEE Transactions on Geoscience and Remote Sensing.