Omnidirectional electromagnetic signal inducer (omni-inducer) devices are disclosed. The omni-inducer device may include a housing, which may include a conductive base for coupling signals to ground, and an omnidirectional antenna node including a plurality of antenna coil assemblies, where the node may be disposed on or within the housing. The omni-inducer device may further include one or more transmitter modules for generating ones of a plurality of output signals, which may be generated at ones of a plurality of different frequencies, and one or more control circuits configured to control the transmitters and/or other circuits to selectively switch the ones of the plurality of output signals between ones of the plurality of antenna coil assemblies.

A method for obtaining gain corrected triaxial electromagnetic propagation measurements with an offset correction includes deploying an electromagnetic logging tool in a subterranean borehole. The logging tool includes at least first and second axially spaced triaxial transmitters and at least first and second axially spaced triaxial receivers. A plurality of full tensor voltage measurements may be acquired and processed tensor term by tensor term to obtain a full tensor, gain corrected quantity. The processing may optionally include (i) removing a full tensor voltage offset from the acquired full tensor voltage measurements to obtain a corresponding plurality of offset corrected voltage tensors and (ii) processing the offset corrected voltage tensor term by tensor term to obtain the full tensor, gain and offset corrected quantity.

A foreign object detection device in the present disclosure includes: a set sensor coil; and a determination device that detects a foreign object, based on voltage of the set sensor coil. A first sensor coil group in the set sensor coil includes unit sensor coils wound in a first winding direction and unit sensor coils wound in a second winding direction opposite to the first winding direction, these coils wound in the respective directions being electrically connected in series. Each unit sensor coil includes a coil conductor prescribing its external shape. Coil conductors are continuously and electrically connected in series. A part or the whole of the coil conductor forming the unit sensor coil in the first winding direction is a part or the whole of the coil conductor forming the unit sensor coil in the second winding direction.

The disclosure is directed to utility locators and associated antenna node support structure devices for allowing a utility locator to self-stand in an upright position without being held or otherwise supported by a user.

The present teaching relates to method, system, medium, and implementations for detecting a target object via a security post. A plurality of sections are arranged in a vertical direction. Each section is designated to detect the target object in a vertical range by receiving information related to magnetic field from one or more sensors, analyzing the sensed information to extract features characterizing the magnetic field variations in the corresponding vertical range, and determining whether the target object is present in the vertical range based on the extracted features. When the target object is detected by a section, an alarm associated with the section is triggered to indicate the detection. An overall detection result is determined based on the detection result from each of the sections and is displayed on a display screen.

A method for detecting a foreign metal object, by way of a charging device, including a microcontroller and a transmitting circuit, having at least one transmitting antenna, which are suitable for charging a portable item of user equipment placed on a charging surface at an operating frequency, the method including a) transmitting a predetermined number of voltage pulses at the terminals of the transmitting antenna, at a parasitic resonant frequency, the parasitic resonant frequency being different and distinct from the operating frequency; b) determining an oscillating frequency of the transmitting circuit; c) if the oscillating frequency is higher than the parasitic resonant frequency, then a foreign metal object is detected on the charging surface.

A method includes using an electromagnetic (EM) tracking system to track a tangible object, detecting a presence of interference with a magnetic field generated by the EM tracking system, and compensating for the interference. A system includes an EM tracking transmitter, an EM tracking receiver, and a processor based apparatus in communication with the EM tracking transmitter and the EM tracking receiver. The processor based apparatus is configured to execute steps including using the EM tracking transmitter and the EM tracking receiver to implement an EM tracking system. A storage medium storing one or more computer programs is also provided.

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 system for metal detection comprises a single aperture comprising two or more sets of detection coils that surround the perimeter of the aperture. A flow path of materials passes through the aperture. Each set of detection coils comprises a transmitter and two receiver coils, with the transmitter coil located between the two receiver coils. Each set of detection coils is at a different angle relative to the flow path.

The present teaching relates to method, system, medium, and implementations for detecting an electronic target object. A magnetic field is first generated. Magnetic field variations associated with presence of an object nearby the magnetic field are observed and analyzed to extract features characterizing the magnetic field variations. Based on such extracted features, it is determined as to whether the object corresponds to an electronic target object. If so, an alarm is triggered to indicate the detection of the electronic target object.