English

Abstract

This study presents experimental measurements of complex dielectric constant at C-band microwave frequency of dry and moist saline soils collected from Dandi (Dist. Navsari) site of Gujarat state (India). An automated microwave set-up tuned at 5.3 GHz frequency is used for this purpose. Measured values of dielectric constant are then used to estimate the scattering coefficient by using perturbation model. Our results indicate relatively lower rate of increase in e' and order of magnitude higher values of e'' for these saline soils when their gravimetric MC is changed from 10 to 30% than that reported for non-saline soils by earlier researchers. Further, at constant value of MC, scattering coefficient of soil sample also increases with increase in the incident angle for vertical polarization, and this increase continues up to angles between 60o to 70o, at which it reaches maximum value and beyond this, it decreases sharply. Further, for vertical and horizontal polarizations, at constant value of incident angle, our results indicate relatively lower rate of increase in scattering coefficient values for saline soils than reported earlier for non-saline soils when gravimetric MC is changed from 10 to 20%. This data is very useful in understanding dielectric behaviour of saline soils and also for designing the active sensors for these soils.