Abstract

Interaction of electromagnetic waves with the materials of planet earth provides the information for microwave remote sensing. From the reflected wave it is possible to reveal the information, which is useful for the measurement of dielectric properties. The dielectric properties of material are function of its chemical constituents and physical properties. Measurements of real (ε’) and imaginary (ε’’) parts of the complex dielectric constant (ε*) of soil with varied moisture content were made at 9.65 GHz. The X-band microwave setup in the TE₁₀ mode with slotted section and a crystal detector is used for  measurements. Infinite sample method is found suitable for measurement of these soils. The measurements are made at room temperature. The dielectric properties of dry soil samples are in good agreement with the earlier work. The value of ε’ and ε’’ first increases slowly and then increase rapidly with moisture content. From this data, the a.c. conductivity and relaxation time are also reported. The result shows the change in electrical properties of dry and moisture-laden soils. These results provide a basis for using high-frequency electromagnetic sensors in the detection of soil moisture content or in ground-penetrating radar. Also precise microwave dielectric measurements of soils and recognition of their dependence on physical and chemical composition are interesting and can be used in support of radar investigations of the Earth’s geology.

Keywords: Dielectric constant, dielectric loss, conductivity, relaxation time.