Nuclear Magnetic Resonance Instrumentation for Geotechnical, Geospatial and Geophysical Investigations

U.S. Army engineers require near-surface moisture content and soil characterization to effectively assess engineered structures (airfield, roads, environmental and construction sites) and natural terrain. Total water content measurements are also invaluable for ascertaining the capability of soil to support mechanized military equipment and operations. Conventional methods are often bulky, invasive and rely on inferred rather than direct measurement of soil moisture. We propose to develop and demonstrate Surface Nuclear Magnetic Resonance (SNMR) geophysical instrumentation capable of measuring near-surface soil moisture content as a function of depth in the top 2 meters of the subsurface. We combine new ultrasensitive compact magnetic sensors integrated with a relatively high-power transmitter and control system into a noninvasive and portable instrument package. A modular design enables integration with time- or frequency-domain electromagnetic (EM) methods yielding enhanced characterization and potential for joint processing and inversion of co-located SNMR and EM data.