Abstract: Apparatus and methods for detecting subsurface tunnels employ an aboveground air pressure sensor and one or more subsurface air pressure sensors. The output of the aboveground sensor forms the input to a numerical model whose input parameters account for the effects of depth and permeability and porosity of the earth on the propagation of pressure variations from the surface to the location of each subsurface sensor. Tunnels are detected on the basis of a growing deviation between measured and modeled subsurface pressures using static model input parameters, or on the basis of changes in the model input parameters required to continue accurately approximating measured subsurface pressures, or on the basis of spatially anomalous values of the model input parameters corresponding to multiple horizontally separated subsurface sensors.

Abstract: Systems, methods, and software for measuring the spatially variable relative dielectric permittivity of materials along a linear or otherwise configured sensor element, and more specifically the spatial variability of soil moisture in one dimension as inferred from the dielectric profile of the soil matrix surrounding a linear sensor element. Various methods provided herein combine advances in the processing of time domain reflectometry data with innovations in physical sensing apparatuses. These advancements enable high temporal (and thus spatial) resolution of electrical reflectance continuously along an insulated waveguide that is permanently emplaced in contact with adjacent soils. The spatially resolved reflectance is directly related to impedance changes along the waveguide that are dominated by electrical permittivity contrast due to variations in soil moisture. Various methods described herein are thus able to monitor soil moisture in profile with high spatial resolution.

Abstract: Systems, methods, and software for measuring the spatially variable relative dielectric permittivity of materials along a linear or otherwise configured sensor element, and more specifically the spatial variability of soil moisture in one dimension as inferred from the dielectric profile of the soil matrix surrounding a linear sensor element. Various methods described herein combine advances in the processing of time domain reflectometry data with innovations in physical sensing apparatuses. These advancements enable high temporal (and thus spatial) resolution of electrical reflectance continuously along an insulated waveguide that is permanently emplaced in contact with adjacent soils. The spatially resolved reflectance is directly related to impedance changes along the waveguide that are dominated by electrical permittivity contrast due to variations in soil moisture. Various methods described herein are thus able to monitor soil moisture in profile with high spatial resolution.

Abstract: A device for inserting a support beneath an object is provided that includes an eversible tubular membrane with a closed end and an open end with the open end sealably connected to a container enclosing a pressurized fluid, wherein the closed end is connected such that it can be retracted under tension through the inside of the tube formed by the radially outward facing aspect of the membrane, and wherein with pressure and/or tension changes the membrane can be eversibly extended and retracted between two surfaces. In addition, the membrane may be co-everted with a sling or draw sheet such that the sling or draw sheet can be inserted between two surfaces along with the membrane. Further, multiple eversible membranes may be inserted between two surfaces or beneath an object or a patient in accordance with the disclosed invention.