A solution for evaluating a medium using electrical signals is described. A plurality of electrical signals having different frequencies are transmitted through the medium and signal data corresponding to the electrical signals after having traveled through the medium is acquired. A complex impedance and a complex permittivity and/or complex conductivity can be calculated for the medium. A set of characteristics of the medium can be computed using mixing models and/or known information of the medium. A level of one or more attributes of the medium can be determined from the characteristics using nonparametric Bayesian inference. One particular application is directed to determining a nitrate level of soil.

A method for localizing an object in the surroundings of an apparatus generating a stray magnetic field, wherein the object has a sensor arrangement including at least one magnetic field sensor, the method comprising: ascertaining at least one item of object information based on (i) stray-field information describing the spatial profile of the stray magnetic field at least within a region and (ii) at least one measured value measured with the sensor arrangement describing a location-dependent property of the stray magnetic field, the at least one item of object information describing at least one of the position or orientation of the object in the region.

A sequence time window amplitude-phase-frequency characteristics analysis method and system for underwater vehicle power frequency electromagnetic field disturbance are provided. The method includes: establishing a power grid dipole group model, emulating and calculating to obtain background field intensity data of a test location, and constructing an emulated background field database; acquiring measured background field data, comparing the emulated data with the measured data, and providing a relative error; calculating a background field intensity and underwater vehicle target disturbance under the action of the above dipole group, and establishing a measured target signal database; and performing actual measurement according to an underwater vehicle motion and detection topology, performing a Fourier transform and Fourier sliding window decomposition after acquiring original data, and acquiring an amplitude spectrum and a spectrogram of an underwater vehicle target disturbance signal.

Disclosed is an inverse estimation-based radius calculation method and system for ferromagnetic target detection. The calculation method includes a data acquisition step and a ferromagnetic target detection radius calculation step. Distrubance of a scale model to power frequency electromagnetic waves is used to inversely estimate a corresponding ferromagnetic target detection radius. Inverse estimation is performed separately for an air layer and a sea water layer according to test results of multiple scale model tests and in consideration of both a stationary state and a motion state of the scale model, so as to acquire a ferromagnetic target detection radius calculation formula. Weights of factors such as mass, speed, depth, and height are great in inverse estimation, so that inverse estimation precision is improved. The majority of background noise interference can be screened out of the power frequency electromagnetic waves.

An apparatus including two or more spaced apart ferromagnetic sensors arranged to detect and screen ferromagnetic objects, and, when a ferromagnetic object is detected, the screening is configured to be substantially independent of the sensor-object distance.

An apparatus including two or more spaced apart ferromagnetic sensors arranged to detect and screen ferromagnetic objects, and, when a ferromagnetic object is detected, the screening is configured to be substantially independent of the sensor-object distance.

A system and method for a smart stand-alone multi-sensor gateway for detection of person-borne threats. The multi-sensor gateway system consists of two pillars comprising a plurality of sensors that build a gateway for patrons to pass through that detects concealed threats carried on-body. The threat detection relies on artificial intelligence (Al) to analyze the sensors’ data and assess the presence of a threat. The Al is performed on an edge device contained within the gateway. The gateway can consist of a plurality of peripherals that enhance the sensing capability of the gateway, such as a camera or an accelerometer, and provide the security guard with information around alerts and threat locations such as with displays or audible alerts and manage the operations such as displays to control throughput.

A current transformer having a body having an upper half and a lower half hingedly connected to the upper half, a pair of ferrite cores located within one of the upper half and the lower half of the body, the pair of ferrite cores defining a gap formed between each ferrite core of the pair of ferrite cores, and a sensor located within the gap formed between each ferrite core of the pair of ferrite cores.

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.

Method and apparatus are provided for detecting objects behind an opaque surface. An exemplary device for detecting objects behind an opaque surface, comprising a housing configured to hold a plurality of components of the device; one or more sensors, coupled to the housing, configured to collect sensor data of an object behind the opaque surface, where the one or more sensors include one or more capacitive sensors attached to an exterior surface of the housing; a controller, residing inside the housing, configured to process the sensor data collected by the one or more sensors; an at least one printed circuit board, residing inside the housing, configured to hold the controller and the plurality of components of the device; and a display configured to convey information about a detected object to a user.