Frequency and time domain measurements using Cross Well Radar to develop testbeds for electromagnetic properties estimation

This paper evaluates a technique to develop appropriate testbeds to take accurate reflection and transmission (s-parameters) measurements and provide accurate electromagnetic (EM) properties estimates of bulk soil using Cross Well Radar (CWR) technology. Frequency domain experimental measurements and electromagnetic simulations using helix antennas show inconsistencies in the s-parameters response, which suggests the use of time domain measurements of an air medium to verify the behavior of a medium with well known EM properties. Time domain measurements results, and the inclusion of extended metal plates in the testbed confirm that energy was entering from top, bottom and edges of the soilbed tank, which was taken into account in the initial simplified analysis. Extended mesh plates reduces the amount of unwanted energy entering the soilbed tank, which lead to more accurate measurements and better estimates of the EM properties for bulk soil.