期刊名称：ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
印刷版ISSN：2194-9042
电子版ISSN：2194-9050
出版年度：2009
卷号：XXXVIII-8/W3
页码：300
出版社：Copernicus Publications
摘要：Dielectric constant values of the samples of soil of Alwar (at various moist states) have been calculated using wave guide cell method at a single microwave frequency 9.78 GHz at 330C. The Backscattering coefficients for rough and bare soil surfaces 0soilσare calculated by Small Perturbation Model (SPM). Fresnal reflectivity of the soil surfaces which is an input parameter for SPM is calculated using the values of dielectric constant of the soil (at different wetness) and observation angle as input parameters. The roughness of soil in SPM is characterized by RMS height and correlation length and isotropic Gaussian auto correlation function. The radar backscattering coefficient of vegetative soil surface is determined by water cloud model. The total back scattering coefficient is calculated adding the contribution of the vegetation, 0vegσand that of the modified effect of underlying soil. The effect of vegetation canopy on the backscattering from bare soil surface is modified by a parameter vegetation transmissivity τ. The present study reveals that radar backscattering coefficient for bare soil surface 0soilσand vegetative soil surface 0ppσhas a respective correlation withSMC of the soil. Further,0so ilσand0ppσdecrease as the angle of observation increases
关键词：Active Microwave Remote Sensing; Back Scattering Coefficient; Soil Moisture Content; Vegetation; Small Perturbation Model
