SOIL DIELECTRIC CONSTANT ESTIMATION USING GNSS REFLECTOMETRY AND THE INTERFERENCE PATTERN TECHNIQUE

Abstract

In this work we present an innovative and low-cost way to estimate the dielectric constant of real soils -which is related to soil moisture- using GPS satellite signal. The trajectory of the satellites was followed with an automated device, and with an antenna type patch was measured the interference pattern generated by the direct GPS signal and that reflected by the ground. To analyze the acquired signal, an electromagnetic dispersion model based on the method of small perturbation was used, which may include stratifications in the underground and from which the dielectric constant that best fits the measurements was obtained. These values were compared with the obteined using a sensor that measures the soil dielectric constant textit in-situ. The comparisons shows that the method based on the interference pattern provides satisfactory results to estimate the dielectric constant of real bare soils. Finally, proposals are outlined to improve the results obtained in this work.