Temperature dependent dielectric model at 1.4 GHz for an agricultural soil thawed and frozen

Abstract

A mono-frequency dielectric model for the agricultural soil both thawed and frozen has been developed. The model is based on the soil dielectric measurements carried out in the ranges of volumetric moisture from 0,03 to 0,51 cm3/ cm3, dry soil density from 1.12 to 1.64 g/cm3, and temperature from -30 to 25°C (heating run), at the frequency of 1.4 GHz used in the SMOS mission. To fit the results of measurements of the soil complex refractive index (CRI) as a function of soil moisture, the refractive mixing model was applied. As a result, the parameters of the refractive mixing model linked to soil solids, as well as the bound, transient, and free soil water components were derived as a function of temperature. The error of the proposed dielectric model was shown to be in the order of the dielectric measurement error itself.