Abstract: The present disclosure relates to a transmitter for a Pulsed Eddy Current system, configured to generate a changing electromagnetic field which induces eddy currents in an object of an electrically conductive material arranged within the electromagnetic field. The transmitter includes a switching device and a transmitter coil configured to be connected to a voltage source. The switching device is arranged for switching a current generated by the voltage source through the transmitter coil. The transmitter coil comprises a plurality of parallel electrically conductive coil layers with a respective damping resistor connected across each of the coil layers, each of the coil layers being connected in series with a respective diode.

Abstract: Provided is a method for detecting a metal target in soil using a metal detector including the steps of generating a transmit magnetic field for transmission into the soil using a transmit winding based on a transmit signal; receiving a first receive magnetic field using the transmit winding during a receive period to produce a first receive signal; and receiving a second receive magnetic field using a receive winding during the receive period to produce a second receive signal. The transmit winding and the receive winding are separated spatially; and producing an indicator output signal based on the first receive signal, the second receive signal and at least one synchronous demodulation function. The first receive signal includes first parameters that define a first transfer function transforming the first receive magnetic field into the first receive signal.

Abstract: 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.

Abstract: A metal detection apparatus that can accurately and automatically determine whether a metal passing through the inspection area is a magnetic or non-magnetic metal comprises a detection unit quadrature-detecting a differential detection signal of magnetic field fluctuation in the inspection area due to the passage of a workpiece, and a determination unit that determines the presence or absence of a mixed metal based on both fluctuation components after the detection. The determination unit compares sample signal phase data obtained beforehand from the detection signal of the magnetic field fluctuation in the inspection area due to the passage of various metal samples, with the signal phase data obtained from the detection signal of the magnetic field fluctuation in the inspection area due to the passage of the workpiece mixed with metal, and determines the type of metal passing through the inspection area based on the phase determination result.

Abstract: Locating system for machine tools including a machine tool for working on a object's machining surface by removing material and movement apparatus for placing in direct contact with the machining surface and for moving the machine tool with respect to the object while the tool works on the object, at least two locating apparatuses each including supporting portion for placing at a fixed point on the machining surface, detector including first cable or second cable for connecting the locating apparatus to the machine tool, and a locating portion to release or receive the cable to measure distance detected between the machine tool and locating apparatus. The detector is configured to allow mutual connection of the locating apparatuses to allow direct measurement of distance between locating apparatuses and distance is further obtainable indirectly from the distances detected by the detector between the machine tool and locating apparatuses.

Abstract: The magnetic detection system 100 is provided with a magnetic sensor 1, a storage unit 5, a first determination unit 42 for outputting whether or not the magnetic body 90 has passed as a first determination result 20, a second determination unit 43 for outputting whether or not the magnetic body has passed as a second determination result 21, a display unit 6 for displaying (notifying) the first determination result and the second determination result. The second determination unit is configured to have higher determination accuracy than the first determination unit.

Abstract: The present application provides a point cloud data processing method, an apparatus, a device, a vehicle, and a storage medium, the method includes: acquiring, according to a preset frequency, raw data collected by sensors on a vehicle; and performing, according to the raw data of the sensors, data fusion processing to obtain a fusion result. By acquiring, according to the preset frequency, the raw data collected by the sensors on the vehicle in a latest period, and performing the data fusion processing to obtain the fusion result, a synchronous clock source may be removed, a weak clock synchronization may be realized, and the cost may be effectively reduced. The preset frequency may be flexibly set, which, when set with a larger value, can reduce a time difference between the raw data of the sensors and improve data accuracy.

Abstract: A multi-sensor electromagnetic (EM) system and method for measuring gradients of EM signals. The multi-sensor EM system includes a frame; a transmitter device attached to the frame and configured to generate a primary EM field; a receiver device attached to the frame and configured to record a secondary EM field generated by the earth after being excited by the primary EM field; and a gradient sensor device attached to the frame and configured to record a gradient of the secondary EM field.

Abstract: A metal detector for detecting a target, the metal detector including: a transmitter for transmitting a transmitted magnetic field; a receiver, including a winding with a plurality of turns, for receiving a magnetic field; and a receive electronics connected to the winding for receiving signals from the winding. The receiver further includes an electrostatic screen covering at least part of the winding. The electrostatic screen is connected to an electronic circuit to receive signals from the receiver to reduce an effective capacitance presented by the electrostatic screen to the winding.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for ground control point assignment and determination. One of the methods includes receiving information describing a flight plan for the UAV to implement, the flight plan identifying one or more waypoints associated with geographic locations assigned as ground control points. A first waypoint identified in the flight plan is traveled to, and an action to designate a surface at the associated geographic location is designated as a ground control point. Location information associated with the designated surface is stored. The stored location information is provided to an outside system for storage.

Abstract: A system includes a metal detector, a structure to hold the metal detector, and a processing unit which processes the measured signal from the metal detector. The measured signals of known objects are recorded with the metal detector. The signals are processed into sets of variables. When an unknown object is detected by the metal detector, the measured signal is processed into the same variables. The variables from the measured signal are compared against the variables in the database. If a match is found, the unknown object is determined.

Abstract: Disclosed is an electromagnetic prediction method for concealed orebodies. A factor associated with an observation direction and a factor associated with a frequency are retrieved from tensor impedance data after static shift recognition and correction. An electromagnetic recognition factor including anisotropic characteristics is constructed. A probability of a developed orebody in a particular underground depth range of a target area is then inferred by using the electromagnetic recognition factor alone or as a component of comprehensive prediction information. Due to the full use of a potential correlation between anisotropic characteristics of frequency domain electromagnetic fields and an apparent metal factor and two-dimensional (or three-dimensional) extended concealed orebodies, the success rate of predicting spatial locations and attributes of the concealed orebodies is improved.

Abstract: An apparatus determines the composition of a metal artifact. The apparatus includes an electrical current source, a metal artifact to be tested, two electrical cables, and a first electrical cable and a second electrical cable different from the first electrical cable. Each of the first electrical cable and the second electrical cable is connected between the electrical current source and the metal artifact. During a test, the electrical current source outputs current. When the electrical current source outputs the current, the current travel through at least a portion of the metal artifact. The apparatus further includes a magnetic field sensor that detects, during the test, a magnetic field generated by the metal artifact when the current travels through the at least the portion of the metal artifact. The magnetic field sensor is disposed within a predetermined distance of the metal artifact during the test.

Abstract: A drilling area network hub is located proximate to a drill rig and includes an uphole transceiver in bidirectional communication with a downhole transceiver by utilizing the drill string as an electrical conductor. Certain information is collected including rig-based and/or location information. At least one field report is generated based on the certain information to characterize at least one of an inground operation, an operational condition of the downhole transceiver, an operational condition of the uphole transceiver, and an operational condition of the drill rig. A drilling area network server receives the field report from the Internet at a remote location and can generate a custom report and/or recommended actions based on field data. Region specific parameters can be applied to the operation of a drilling system. The drilling area network hub can transfer data logs to the remote location according to assigned priorities.

Abstract: An inductive position sensor is configured to determine a position of a target device. The inductive position sensor comprises at least two coils for determining said position. At least two of the at least two coils for determining the position at least partially overlap. The at least two coils each have a plurality of portions being equally distributed over N substantially parallel planes, with N being an integer larger than or equal to two. For each of the at least two coils the portions distributed over the N substantially parallel planes are substantially identical, so that mutual inductance between the at least two coils is substantially unaffected by misalignments between the N substantially parallel planes.

Abstract: A fluxgate detector for buried and abandoned chemical weapons is provided, comprising: a probe for sensing an external magnetic field, comprising a probe input and a probe output; an excitation module electrically connected to the probe input for inputting an excitation signal into the probe; a frequency selection module electrically connected to the probe output for isolating a second harmonic signal in an induced voltage generated by the probe; and a signal acquisition module electrically connected to the frequency selection module. The second harmonic signal in the induced voltage can be isolated by the frequency selection module, transmitted to the signal acquisition module, and converted to an intensity of the magnetic field by the signal acquisition module. The substance detected can be identified according to the intensity of the magnetic field, so that the buried ACWs can be found efficiently and accurately.

Abstract: A corrosion prevention survey system for determining locations of faults along an underground structure includes a data collector to record location data and voltage data; a voltage reading system to secure to a leg of a user, the voltage reading system having a pole with a spike to be inserted into a ground surface, the spike being able to read a voltage current running through the ground; an attachment device to secure the pole to the leg of a user; and one or more wires to connect the pole to the data collector; the pole is a predetermined length not greater than 2 feet; the voltage data is transmitted from the pole to the data collector; and the location data and voltage data are used in analysis to determine directions of voltage gradients for further determination of location of faults along the underground structure.

Abstract: The present invention relates to an inductive position sensor configured to determine a position of a target device, comprising at least one receiving coil arranged to receive a magnetic field and an inner transmitting coil winding and an outer transmitting coil winding arranged to generate said magnetic field, whereby said at least one receiving coil is positioned between said inner transmitting coil winding and said outer transmitting coil winding and whereby said inner transmitting coil winding and said outer transmitting coil winding are so arranged that current flows in the same sense.

Abstract: A system includes a metal detector, a structure to hold the metal detector, and a processing unit which processes the measured signal from the metal detector. The measured signals of known objects are recorded with the metal detector. The signals are processed into sets of variables. When an unknown object is detected by the metal detector, the measured signal is processed into the same variables. The variables from the measured signal are compared against the variables in the database. If a match is found, the unknown object is determined.

Abstract: A mobile detection device evaluating a depth of an occluded underground elongate utility line. The device comprises at least a first and a second detector unit, each comprising at least a detection loop and corresponding transmitting loop arranged close together. The device also comprises at least one excitation coil for emitting an alternating electromagnetic excitation field with its emission direction substantially in line with the sensitivity direction of the detection loop. The device has an electronic signal evaluation unit for detecting the utility line according to an electrical signal induced in the detection loops and evaluating the depth according to a difference of the electrical signal in-between the detection loops. There is a compensation unit built to apply an electrical signal to the transmitting loops for establishing a compensation field, which nullifies influences of direct coupling residuals of the excitation field at the detection loops.

Abstract: An unmanned underwater vehicle (UUV) with a hydraulic system (100) for use in cold surroundings and method of controlling such hydraulic system. The hydraulic system (100) comprises a hydraulic circuit (10). One or more tools (21,22) may be hydraulically operable via the hydraulic circuit (10). A pump (32) is configured to pressurize a flow of hydraulic fluid (F) via the hydraulic circuit (10) e.g. for actuating the tools (21,22). A valve system (40) comprises control valves (41,42,43) disposed in the hydraulic circuit (10) for controlling the flow of hydraulic fluid (F) through the hydraulic circuit (10). A controller (50) is configured to control one or more of the control valves (43) as a function of a temperature (T) of the hydraulic fluid (F).

Abstract: Systems and methods are disclosed for preventing damage to underground assets caused by earth work or construction equipment and vehicles. The system includes a central data system, which has access to asset location and map data, and a GPS enabled tracking device provided in the vehicle. The system operates by comparing the real-time vehicle location to the stored asset locations, displaying the map, asset information and vehicle location to the vehicle operator and generating alerts when the vehicle breaches a perimeter around an asset. Preferably, both the central data system and the tracking unit are configured to operate together and in parallel, thereby improving the reliability of the system. In addition, the system is also specifically configured to implement various approaches for using and displaying asset location data during monitoring operations while preserving the confidentiality and security of sensitive information.

Abstract: One aspect of the disclosure provides apparatus for detecting an object. The apparatus comprises a sense coil. The apparatus comprises a processor configured to determine an amount of change in a reactance of the sense coil from a previous reactance value for the sense coil. The processor is configured to determine an amount of change in a resistance of the sense coil from a previous resistance value for the sense coil. The processor is configured to determine a presence of the object based on a relationship between the amount of change in the reactance of the sense coil and the amount of change in the resistance of the sense coil. The processor performs an inverse tangent operation on a quotient of the amount of change in the reactance of the sense coil divided by the amount of change in the resistance of the sense coil.

Abstract: A method and system for estimation of electromagnetic earth responses in a marine electromagnetic survey. A method may comprise estimating initial values of the electromagnetic earth responses and ambient noise applicable to the marine electromagnetic survey; and processing electromagnetic data based on the initial values of the electromagnetic earth responses and the ambient noise to obtain a joint estimation of updated values of the electromagnetic earth responses and the ambient noise, wherein the electromagnetic data was acquired with one or more electromagnetic sensors, wherein the electromagnetic data contains measurements of an electromagnetic field.

Abstract: A technique is directed to transporting data storage equipment. The technique involves electronically activating monitoring circuitry which is co-located with the data storage equipment. The technique further involves, after the monitoring circuitry is electronically activated, receiving location data from the monitoring circuitry while the data storage equipment is en route from a first ground location to a second ground location. The technique further involves, based on the location data, performing a set of location evaluation operations to determine whether the data storage equipment is on course along a predefined route between the first ground location and the second ground location.

Abstract: In a first technique one or more tuned circuits (“traps”) are placed in series in the metal detector coil, tuned to the operating frequency of the other sensor. In another technique a single turn coil of wire, or a small number of turns coil, is used as the metal detector coil, in combination with a step up transformer at the coil feed, to increase the EMF of the coil. In a further technique, the metal detector coil is formed in a plane that has regard to the sensing field of the other sensor. In another technique, the feed for the metal detector coil comprises a twisted pair of wires, which are routed along an axis in order to try to minimize and equalize the effect of the metal detector feed on the operation of the other antenna.

Abstract: A proximity sensor includes a transmission circuit that periodically supplies an excitation current in a pulse form to a detection coil for generating a magnetic field, a reception circuit that detects voltages or currents generated at both ends of the detection coil by the periodic supply of the excitation current, and a controller that detects presence or a position of the detection body by utilizing a time series signal obtained by the detection. The controller acquires a factor that influences the detection of the detection body in a first period of the time series signal. The controller compensates a signal in a second period of the time series signal by the factor. The controller detects the presence or the position of the detection body on the basis of a signal after the compensation.

Abstract: The present invention features a unique system of interdependent methods to greatly improve data acquired via the Differential Target Antenna Coupling (“DTAC”) method, which transmits electromagnetic (“EM”) fields and measures the primary EM field and the secondary EM fields generated in subsurface targets. These new data correction techniques provide improvements, in orders of magnitude, to the measured DTAC response accuracy. This improvement allows for greater depth of investigation, improved target location, and enhanced target characteristics.

Abstract: A high-dimensional variable selection unit determines a list of critical parameters from sensor data and parametric tool measurements from a semiconductor manufacturing tool, such as a semiconductor inspection tool or other types of semiconductor manufacturing tools. The high-dimensional variable selection model can be, for example, elastic net, forward-stagewise regression, or least angle regression. The list of critical parameters may be used to design a next generation semiconductor manufacturing tool, to bring the semiconductor manufacturing tool back to a normal status, to match a semiconductor manufacturing tool's results with that of another semiconductor manufacturing tool, or to develop a specification for the semiconductor manufacturing tool.

Abstract: Exemplary embodiments include a computer-implemented method for configuring at least one antenna array comprising receiving a plurality of sets of samples corresponding to signals incident on a plurality of antennas; computing a mean of the envelopes of the sums of the respective sets; estimating a direction of arrival of the signals incident on the antennas based on the computed means; and configuring the antenna array based on the estimated direction of arrival. The computing and estimating procedures can be performed for each of a plurality of direction-of-arrival candidates. The estimating procedure can comprise determining a maximum value of the mean and a direction of arrival corresponding to the maximum value. The spatial selectivity of the antenna array can be configured based on the estimated direction of arrival. Other exemplary embodiments can include communication apparatus and computer-readable media embodying one or more of the exemplary computer-implemented methods and/or procedures.

Abstract: A sensor arrangement for determining at least one physical parameter of a sensor unit which is activated by at least one periodic excitation, comprising a detection region in which changes of the parameter in the surroundings of the sensor unit lead to an output signal from the sensor unit. The sensor unit is wired such that if there is no change of the parameter in the detection region the output signal is a zero signal at the output of the sensor unit, whereas if there are changes of the parameter in the detection region the output signal is a signal that is not zero and which has a specific amplitude and phase. By means of a closed-loop control, the non-zero signal in the receive path is adjusted to achieve an adjusted state at zero even in the presence of changes of the parameter in the detection region. Inherent in the control signal used for this adjustment is a deviation (?x, ?y) of the control signal from the adjusted state, which deviation represents information about the parameter.

Abstract: An electronic feeler gauge comprises a sensor blade, a transmitting system, and a receiving system. The sensor blade comprises transmission induction coils, reception induction coils, and measurement sites, spaced in two dimensions about the sensor blade. Each of the measurement sites is associated with at least one of the transmission induction coils and at least one of the reception induction coils. The transmitting system is configured to drive direct electrical current across the transmission induction coils to produce transmitted probe signals from the transmission induction coils. The receiving system is configured to receive response signals from the reception induction coils due to the transmitted probe signals.

Abstract: The DC leakage current detector for detecting leakage current in a DC bus includes a pair of transformers each comprising a magnetic core and excitation and detection windings would about the magnetic core, with the magnetic core positionable about a pair of conductors that create a magnetic field that is a sum of currents in the conductors. An excitation and biasing circuit is connected to the excitation winding in each transformer to inject a current signal thereto that creates a changing magnetic flux in the core of each transformer and a detector output connected to the detection winding in each transformer to receive a voltage therefrom generated responsive to the magnetic flux in the core of each transformer, wherein the voltage on the detection windings provides a net voltage at the detector output whose value is indicative of a presence of a leakage current on the DC bus.

Abstract: Foreign objects in a conveyed product stream of granular or chunk polysilicon is effected by identifying the foreign objects by eddy current sensors in the conveyor by which the granular or chunk polysilicon is being conveyed.

Abstract: The present invention discloses a dual-technology sensor head tightly integrating an Electromagnetic Induction (EI) sensor coil for detection, localization and discrimination of metal in mines and Improvised Explosive Devises (IED), and a dual polarized Ultra-Wideband (UWB) radar antenna array for Ground Penetrating Radar for detection, localization and discrimination of same. The core challenge addressed is how to prevent the EI sensor from detecting the metal in the UWB antenna which then desensitizes the EI sensor and degrades its dynamic range. The key characteristic of the new UWB radar antenna design is its very low magnetic induction, thereby imposing very little degradation to the EI coil. Additionally, the UWB antenna array incorporates unique design features to enhances its low frequency performance for better penetration of the ground. Through the design guidelines taught herein the EI sensor has been demonstrated to incur no degradation from the proximate UWB array.

Abstract: A system for measuring electric characteristics of an earth formation includes a carrier configured to be disposed in an earth formation, and an inductive measurement assembly including an antenna configured to generate an oscillating magnetic field in the earth formation and measure a resistivity of the formation by detecting a signal in response to currents induced in the formation. The system also includes a capacitive measurement assembly including a capacitive measurement electrode configured to detect a signal in response to a measurement current injected into the formation, the capacitive measurement electrode disposed between the antenna and the formation and in a path of the magnetic field, the capacitive measurement electrode formed from a plurality of constituent electrodes that are electrically isolated from each other so as to prevent induction of eddy currents across the plurality of electrodes.

Abstract: A wearable computing device includes an input device, a global positioning system (GPS) sensor, an inertial measurement unit (IMU), a camera, and a memory that is designed to store a database of landmarks and corresponding locations. The device includes a mobile processor that is designed to receive first user input indicating that the user is traveling from a starting location to a destination location and second user input indicating that new landmarks are present. The processor is designed to determine locations of the new landmarks based on the current location, the inertial measurement data, and/or the detected image data. The processor is designed to update the database to include the new landmarks and corresponding locations. The processor is designed to update the database to include an ordered list of landmarks including the new landmarks in order of their appearance from the starting location to the destination location.

Abstract: A metal detector has a large primary transmit coil, a small primary feedback bucking coil, a first receive coil, and a second receive coil. A variable resistance device is connected to the first and second receive coils. A voltage source is connected to the large primary transmit coil. The voltage source is oppositely connected to the small primary feedback bucking coil. A primary voltage is provided to the large primary transmit coil. A reverse primary voltage is provided to the small primary feedback bucking coil. The small primary feedback bucking coil is positioned near the first and the second receive coils. The metal detection methods and apparatus sums up the signals from the two secondary coils. One is over nulled, the other is under nulled. They are close enough to an inductive null to attenuate the stray coupled signals from the primary driving signal and detecting the object.

Abstract: Various embodiments are described that relate to a loop with a constant phase. The loop can function as an antenna and be used in object detection. A current source can be used to power the loop such that the loop produces a magnetic field and electric field. The magnetic field can be powerful enough to detect a dielectric while the electric field is so small that it does not interfere with nearby communication equipment. Thus, detection can occur without disruption of other important devices.

Abstract: Buried object locator systems including transmitters and associated buried object locators using phase-synchronized signals are disclosed. A transmitter may generate output current signals that are phase-synchronized with a corresponding locator for improved utility locating.

Abstract: A method, system, and medium are provided for dynamically adjusting an angular orientation of cross-polarized antenna array elements to optimize select radio-frequency (RF) parameters. RF uplink signals are received from a plurality of mobile devices, and the signals are analyzed to determine parameters associated with signal strength and/or signal quality. Based on the determination, a first set of cross-polarized antenna array elements are deactivated and a second set of cross-polarized antenna array elements are activated, where the second set of antenna array elements has a different angular orientation relative to the first set of antenna array elements. Activation enables the second set of antenna array elements to transmit and receive communication signals.

Abstract: A transmitter for use in an inground tool transmits a locating signal for tracking an underground position of the inground tool. The locating signal is characterized by a transmission frequency which changes responsive to detecting a roll orientation pattern in which the transmitter is held stationary for a predetermined period of time.

Abstract: An apparatus for checking for a presence of an electrically conductive body has at least one transmitting device and at least one receiving device. The transmitting device provides a transmission signal in the form of a magnetic field. The receiving device generates a reception signal from the transmission signal that is induced into the receiving device. The transmitting and receiving devices are configured in such a way that, when the electrically conductive body is absent, partial reception signals form in the receiving device on account of the induced transmission signal and the partial reception signals substantially cancel one another out in the reception signal.

Abstract: A sensor for the location of metallic objects and also an associated method comprise a plurality of transmitting coils (2.1, 2.2) and at least one receiving coil (1.9) which are arranged such as to be inductively coupled to one another and overlap to a partial extent for the purposes of decoupling the interaction therebetween, whereby there can be obtained a point of optimal cancellation of the interaction. Due to the fact that a flow of current is passed through the transmitting coils (2.1, 2.2) by a sensor electronic system, equal flows of current through the transmitting coils have an effect upon the at least one receiving coil (1.9) which results in a local point of optimal cancellation which moves in a first direction when there is a flow of current in a first transmitting coil (2.1), whereas it moves in another direction when there is a flow of current in a further transmitting coil (2.

Abstract: A method for reducing unwanted signals, due to a back emf decay, within a receive signal received by a receive coil of a metal detector during a demodulation of the receive signal after a transmission by a transmit coil of the metal detector, including controlling a T/R switch to control a characteristic of the back emf decay to reduce a duration of the period of the back emf decay.

Abstract: Various embodiments are described that relate to a loop with a constant phase. The loop can function as an antenna and be used in object detection. A current source can be used to power the loop such that the loop produces a magnetic field and an electric field. The magnetic field can be powerful enough to detect a dielectric while the electric field is so small that it does not interfere with nearby communication equipment. Thus, detection can occur without disruption of other important devices.

Abstract: An apparatus, system and method for detecting defects in building structures is provided. The apparatus includes a detector operable to determine an indication of the defect; and a transmitter operable to wirelessly transmit the indication from the apparatus to a central controller. The system includes the detection unit; a locator operable to determine the location of the detection unit; and a memory for storing the indication and the location in association with each other. The memory may be part of a central controller in wireless communication with the detection unit. The apparatus or central controller may include a processor operable to determine from a plurality of measurements performed by the detection unit a resultant measurement vector indicating a direction from the detection unit toward the defect. The detection unit may be operable to autonomously change its location. A display showing resultant measurement vectors at various locations can be produced.

Abstract: The invention relates to a security and/or value document having a security feature, to an ink for making the security feature, to a method for making such a security and/or value document, and to a method for verifying such a security and/or value document.

Abstract: Nulling utility locators including a transmitter element, a sensing element, and an electronic circuit for processing signals from the transmitting element to at least partially cancel each other and determine information associated with a buried utility are disclosed.

Abstract: Various embodiments are described that relate to a loop with a constant phase. The loop can function as an antenna and be used in object detection. A current source can be used to power the loop such that the loop produces a magnetic field and electric field. The magnetic field can be powerful enough to detect a dielectric while the electric field is so small that it does not interfere with nearby communication equipment. Thus, detection can occur without disruption of other important devices.