The present invention discloses a method and apparatus for simulating and designing structural parameters of an air-core coil. The method for simulating and designing structural parameters of the air-core coil includes: building an impedance function of the air-core coil according to a structural parameter variable, the air-core coil being of a differential structure and being wound in a completely parallel winding fashion; building an index function of the air-core coil by calculating an equivalent bandwidth, sensitivity and an equivalent noise power spectrum by means of the impedance function. The method is intuitive, and makes calculation of the optimized technological and structural parameters easier and more convenient, thus reducing the amount of calculation and shortening the calculation time.

Electromagnetic tracking systems and methods for automatically providing the required additional information needed to identify the orientation of a sensor are disclosed. The tracking systems are configured to carry out a digital modulation process to determine one or more parameters needed for calibration and to determine if the carrier wave and the modulated signal are in-phase or 180° out-of-phase at time T=0, thereby determining the operational sign of the carrier wave and thus the orientation of the one or more sensors. In some embodiments, at least one offset coil is arranged to generate an additional magnetic field, and the tracking system may be calibrated on the basis of the additional magnetic field.

A magnetic field communication method and apparatus using a giant magnetoimpedance (GMI) magnetometer are disclosed. The magnetic field communication apparatus includes a GMI magnetometer configured to detect a first communication signal based on a received magnetic field signal, a first signal extractor configured to extract a second communication signal comprising a message signal from the first communication signal, a second signal extractor configured to extract a third communication signal by removing a magnetization frequency signal from the second communication signal, and a third signal extractor configured to extract the message signal by removing a carrier wave frequency signal from the third communication signal.

A method of operating a head mounted augmented reality display system includes producing an electromagnetic field using an electromagnetic emitter, positioned in a handheld controller and reflecting the electromagnetic field using a first electromagnetic reflector, positioned adjacent to the electromagnetic emitter, to form a modified electromagnetic field. The method also includes reflecting a portion of the modified electromagnetic field using a second electromagnetic reflector positioned in a headset and detecting the reflected portion of the modified electromagnetic field by an electromagnetic sensor positioned adjacent to the second electromagnetic reflector.

An exemplary method of indicating a condition of grout within a post-tensioned tendon involves positioning a magnet and a metallic sensing plate in close proximity to an outer surface of the post-tensioned tendon; rotating the magnet and the metallic sensing plate around the outer surface of the post-tensioned tendon; measuring an amount of magnetic forces applied to the magnet during rotation of the magnet around the post-tensioned tendon; measuring an impedance between the metallic sensing plate and metallic strands within the post-tensioned tendon during rotation of the metallic sensing plate around the post-tensioned tendon; and generating an image of a cross-section of the post-tensioned tendon indicating one or more grout conditions in spatial proximity to the metallic strands within the post-tensioned tendon based on measurement data using the magnet and the metallic sensing plate.

A magnetic detection system is provided which is usable in a movable body including a power receiving system that receives power from a power transmission system by electromagnetic induction. The magnetic detection system includes at least one magnetic flux measuring unit that detects a magnetic flux including a magnetic source magnetic flux from a magnetic source disposed on the ground, and a signal processing unit that suppresses influence of a magnetic flux generated from the power receiving system on the magnetic flux measured by the magnetic flux sensor unit, to detect the magnetic source magnetic flux.

A method for monitoring the operating state of a set of circuit breakers includes the steps of arranging on the wall of each circuit breaker a synchronous triaxial digital magnetometer on a semiconductor chip, cyclically and synchronously reading temperatures measured by the magnetometers and from the temperatures measured by the magnetometers and a value of the ambient temperature, determining, for each circuit breaker, whether an internal heating temperature of the circuit breaker reaches a first temperature threshold which may be representative of an anomaly of the operating state of the circuit breaker.

A magnetometer includes an electron spin defect body including a plurality of lattice point defects. A microwave field transmitter is operable to apply a microwave field to the electron spin defect body. An optical source is configured to emit input light of a first wavelength that excites the plurality of lattice point defects of the electron spin defect body from a ground state to an excited state. A first optical fiber has an input end optically coupled to the optical source and an output end. The output end is attached to a first face of the electron spin defect body and is arranged to direct the input light into the first face of the electron spin defect body. A second optical fiber has an output end and an input end. A photodetector is optically coupled to the output end of the second optical fiber.

A magnetometer includes an electron spin defect body including a plurality of lattice point defects. A microwave field transmitter is operable to apply a microwave field to the electron spin defect body. An optical source is configured to emit input light of a first wavelength that excites the plurality of lattice point defects of the electron spin defect body from a ground state to an excited state. A first optical fiber has an input end optically coupled to the optical source and an output end. The output end is attached to a first face of the electron spin defect body and is arranged to direct the input light into the first face of the electron spin defect body. A second optical fiber has an output end and an input end. A photodetector is optically coupled to the output end of the second optical fiber.

An example device includes a first gradiometer that includes a first set of sensing elements aligned along a first axis, a second gradiometer that includes a second set of sensing elements aligned along a second axis, and a controller. The first set of sensing elements and the second set of sensing elements may be configured to sense a set of magnetic field components that are perpendicular to the rotational axis, wherein the first axis is in a first plane and the second axis is in a second plane, and the first plane and the second plane may be perpendicular to a rotational axis of a rotatable object. The controller may obtain, via the first gradiometer and the second gradiometer, the set of components of the magnetic field. The controller may then determine, based on obtaining the set of components of the magnetic field, the angular position of the rotatable object.