Attenuation of GPR signal to detect variation in mineral concentration

Abstract

NASA’s plan to build a base on the Moon necessitates employing a vital lunar resource to support life in the base due to the high cost of transportation and logistics. Ilmenite is believed to be one of the best performing minerals to serve the need. Ground Penetrating Radar (GPR) can be utilized to detect Ilmenite within lunar regolith due to its significant metal content. GPR capability was tested in a prototype laboratory experiment to detect Ilmenite. A small lens of powdered Ilmenite buried in fine grain silica rich sand showed prominent reflection characteristics to the electromagnetic waves. The proceeding step for a feasible mining operation requires detecting the highest possible concentrations of Ilmenite within a survey area. The electromagnetic waves transmitted from an antenna are modified within the host medium due to the changes in mineralogy and chemistry. Therefore, the change in reflected back energy of the electromagnetic waves can be indicative of the change in concentration of the Ilmenite. The reflected energy of the GPR signal was used to provide information about the variation in concentration of the Ilmenite. In order to test the feasibility of the methodology, a full size field survey in Mineral Springs, Arkansas was conducted. The site is known to have variable concentrations of Ilmenite.