Abstract: Discriminating between a cable locating signal and a false cable locating signal is described. A reference signal, which contains a locating signal frequency impressed on it, is transmitted in a way which provides for detection of a phase shift between the locating signal and the false locating signal. Based on the phase shift, a receiver is used to distinguish the locating signal from the false locating signal.

Abstract: Electromagnetic proximity detection method for a buried structure executed with a mobile detection device, including sensing an electromagnetic field emitted from the structure as an analog electrical signal and digitalizing the analog electrical signal as a digital signal, performed after or while filtering the analog and/or digital signal. The proximity of the buried structure is determined by analyzing the digital signal, wherein the detection method can be alternatively executed in at least two of the following modes of detection: Power-Mode of detection, Radio-Mode of detection or Active-Mode of detection. An additional Switching-Mode of operation includes a repeated sequential detection in at least two of the mentioned modes of detection and is done by automatic subsequent alternating of the mode of detection with a minimum rate of alternation that an area of detection is coverable by the at least two modes of detection in a single execution of the detection method.

Abstract: A magnetic signal noise reduction and detection system has inputs configured to receive data from a first total field scalar magnetometer, data from a vector magnetometer, and data from a position, velocity and heading sensor, a signal processor configured with a pre-processor system, an adaptive noise cancellation system and a detection system, the pre-processor system configured to carry out initial processing of data received. The pre-processor is configured to convert data to the frequency domain and pass the converted data to the adaptive noise cancellation system. The adaptive noise cancellation system is configured to carry out multivariate regression on the converted data to reduce detected noise. The detection system is configured to detect magnetic anomalies and output information in real time about the magnetic anomalies to a user interface.

Abstract: An apparatus monitors a positional relationship between a boring tool and an inground line and includes a transmitter to generate a magnetic locating field from one of either the boring tool or at least an underground length of the line. A receiver can be carried by the boring tool if the field is generated from the line, or connected to the line if the field is generated from the boring tool, to detect an intensity of the magnetic locating field to produce a signal indicative of the magnetic field intensity with the signal being responsive to the positional relationship between the boring tool and the line. A display produces an indication responsive to the signal based on the detected intensity of the magnetic locating field.

Abstract: A system and method of mapping underground utilities and other subsurface objects involves one or more of acquiring utility location data using a number of different detectors and sensors, processing the multiple detector/sensor output data to produce mapping data, storing the mapping data in a database, and providing access to and use of the stored mapping data by subscribing users on a usage fee basis.

Abstract: A manually operated pedicle locator instrument measures the static permittivity of matter to locate pedicles in vertebral or bony structures. The locator senses and compares the dielectric constants of the pedicle and the surrounding matter. When the operative component of the locator, the component which contains controlled capacitors, is placed over non-pedicle material, the locator will sense one dielectric constant. However, when it is placed over a pedicle, there is a different dielectric constant. The locator operates on this capacitance difference generated by differences in density. Circuitry in the locator senses this change and sends the change signal to indicator lights located on the locator. A switch on the locator allows the surgeon to select different levels of capacitance in order to identify thicknesses of different bony structures, i.e. structures in cervical, thoracic, and lumbar vertebral bodies.

Abstract: Man-portable locator systems for locating buried or otherwise inaccessible pipes, conduits, cables, wires and inserted transmitters using detector arrays and stochastic signal processing and similar techniques to analyze and display multiple target objects at differing frequencies in a layered user interface (UI) are described. In one embodiment, the locator UI may be adapted to present a target plurality sorted by proximity of target conductor to the locator operator together with other useful information specifying the multiple objects, frequencies and changes in the subterranean landscape by means of a useful combination of graphical, numeric and acoustic representations.

Abstract: Marking information relating to use of a marking device to perform a marking operation may be acquired from one or more input devices, logged/stored in local memory of a marking device, formatted in various manners, processed and/or analyzed at the marking device itself, and/or transmitted to another device (e.g., a remote computer/server) for storage, processing and/or analysis. In one example, a marking device may include one or more environmental sensors and/or operational sensors, and the marking information may include environmental information and operational information derived from such sensors. Environmental and/or operational information may be used to control operation of the marking device, assess out-of-tolerance conditions in connection with use of the marking device, and/or provide alerts or other feedback. Additional enhancements are disclosed relating to improving the determination of a location (e.g.

Abstract: The invention concerns a proximity detection of buried conductive structures before or while digging in areas being excavated. By means of the enclosed methods, devices, and setups, the ability and accuracy of the detection of underground structures, such as conduits, pipes, etc. is improved by conductively applying a current into the structure through the soil. The thereby emitted electromagnetic field is detected by a movable detection-unit over ground. According to this electromagnetic field the detection-unit can determine the proximity of the structure and issue a warning signal. This warning signal helps an operator of an earth moving machine to avoid a collision with the structure.

Abstract: An electronic device for detecting an object beneath a wall section of interest has an elongate rectangular base for temporarily mounting to the wall section of interest and for carrying a display panel to display a persistent image of the object. The device can be a two-part device comprising a first part comprising a light projector and a second part comprising a sensor. The device can also be a single part device where the display and the sensor are incorporated into a single body.

Abstract: Devices for and methods of connecting a buried tracer wire to a buried utility pipe are described. The devices and methods include providing a tracer wire connector connected to a clamp, attaching the clamp to a metal portion of the buried utility pipe, and placing an end of the buried tracer wire in the tracer wire connector so that a conductor in the tracer wire is in electrical communication with the buried utility pipe. A sacrificial anode may be conductively attached to the tracer wire connector.

Abstract: Location determination is performed using a transmitter including an elongated generally planar loop antenna defining an elongation axis. The elongation axis is positioned along at least a portion of a path. A magnetic field is then generated which approximates a dipole field. Certain characteristics of the magnetic field are then determined at a receiving position radially displaced from the antenna elongation axis. Using the determined certain characteristics, at least one orientation parameter is established which characterizes a positional relationship between the receiving position and the antenna on the path. The magnetic field may be transmitted as a monotone single phase signal. The orientation parameter may be a radial offset and/or an angular orientation between the receiving position and the antenna on the path. The antenna of the transmitter may be inserted into a first borehole to transmit the magnetic field to a receiver inserted into a second borehole.

Abstract: The invention relates to a method, a device and a system for preventing false alarms in a theft-preventing system comprising a magnetic field for detecting at least one metal object in a first detection zone and means for determining a time-difference; said method comprising the steps of detecting a first change in a parameter indicative of the magnetic field in said first detection zone; detecting a second change in the parameter indicative of the magnetic field in said first detection zone; determining a time-difference between the detection of said first change in said parameter and the detection of said second change in said parameter; and performing an action based on said time-difference. In this way, false alarms due to a metal detector falsely detecting for example movement of metal-doors in a first detection zone may be reduced/eliminated. Additionally, the false alarms due to an opening and/or closing of a door with metal parts acting as an active tag may be reduced/eliminated.

Abstract: A transmitter transmits a locating signal from a boring tool by operating at a frequency that is selected as one of at least two operating frequencies for use in locating the boring tool. A receiver, forming part of the locator, cooperates with the locator to cause the locator to respond dynamically to a change of the selected one of the operating frequencies such that the locator tracks the selected operating frequency.

Abstract: A device rotates at least one static magnetic field about an axis, producing a rotating magnetic dipole field, and is movable in relation to the surface of the ground. The field is periodically sensed using a receiver to produce a receiver output responsive to the field. A positional relationship between the receiver and the device is monitored using the output. In one aspect, changing the positional relationship, by moving the device nearer to a boring tool which supports the receiver, causes an increase in accuracy of depth determination. In another aspect, determination of an actual overhead position of the boring tool, and its application, are described. Use of a plurality of measurements over at least one-half revolution of each magnet is disclosed. Establishing a surface radial direction toward a boring tool and resolution of multi-valued parameters is described. Calibration techniques, as well as a three transmitter configuration are also described.

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: An arrangement and an associated method are described in which a boring tool is moved through the ground within a given region along a path in which region a cable is buried. The boring tool and the cable transmit a boring tool locating signal and a cable locating signal, respectively. Intensities of the boring tool locating signal and the cable locating signal are measured along with a pitch orientation of the boring tool. Using the measured intensities and established pitch orientation, a positional relationship is determined to relative scale including at least the boring tool and the cable in the region. The positional relationship is displayed to scale in one view. The positional relationship may be determined and displayed including the forward locate point in scaled relation to the boring tool and the cable. Cable depth determination techniques are described including a two-point ground depth determination method.

Abstract: This invention provides a pulse induction metal detector where a coil transmits a pulsed magnetic field to energize metal objects that are often buried or hidden in a matrix (ground) containing ferromagnetic minerals. A difficult challenge is to detect and identify the metal object while ignoring the ferromagnetic matrix. Techniques are presented for achieving this.

Abstract: A portable locator and method for establishing the location of the cable line in a region which includes at least one generally straight electrically conductive cable line extending across the region from which cable line a locating signal includes a first arrangement for measuring a local flux intensity of the locating signal at a first above ground point within the region with the portable locator in a particular orientation at the first above ground point. A second arrangement uses the local flux intensity to establish a cable line angular orientation which limits the possible directions to the cable line relative to the particular orientation of the portable locator at the above ground point. A third arrangement uses the measured local flux intensity to establish an actual direction of the cable line that is selected from the possible directions based on certain characteristics of the locating signal.

Abstract: The present invention is a metallic sensing ground probe comprising a rod and a handle having a port for storing a power supply in electrical communication with a circuit, for generating an electric field between a sensor tip on a distal end of the rod and a logic circuit for actuating an LED in an LED display unit on the handle, when the sensor tip encounters a metal object within the ground thus completing the circuit.

Abstract: A sensing system comprises a material having a matrix structure in which a plurality of sensing elements are embedded, the sensing elements having electron distribution and/or transport properties that change in response to a change in a physical or chemical property of the material. The sensing system further comprises a receiver, including an antenna, the receiver arranged to receive a source RF signal and a returned RF signal, the returned RF signal being received from the material. A change in the electron distribution and/or transport properties of the sensing elements cause the source RF signal to change, such that a change in a property of the material can be determined from the returned RF signal. A corresponding method of sensing a change in a property of a material is also provided.

Abstract: A self-calibrating magnetic field monitor is disclosed. In one embodiment, a magnetic field sensor repeatedly generates an electronic signal related to the magnetic field. In addition, a calibration module generates a relative baseline signal based on an average value of the electronic signals for a given time period. A comparator compares the electronic signal with the relative baseline signal and generating an output signal if a difference in the comparing is greater than or equal to a threshold.

Abstract: A communication cable, such as a fiber optic cable, can comprise a conductive tape that extends along the cable and that facilitates locating the cable from a remote location, for example when the cable is buried under ground. The tape can comprise a low resistance for transmitting a locate signal along the length of the cable that can be detected remotely by a detector without exposing the cable. The conductive tape can be circumferentially applied around the core of the cable under the cable's jacket. Thus, the conductive tape can be accessed without exposing the core. The cable can include one or more buffer tubes for housing optical fibers. The buffer tubes and/or the jacket can comprise an antioxidant for preventing degradation associated with contact with copper or other metal of the conductive tape.

Abstract: A holistic approach to management and oversight of locate and marking operations is provided. Initial requests to perform such operations are improved, and such requests are intelligently assessed to appropriately allocate resources to perform operations. Technicians are effectively dispatched and may be provided with process guides to facilitate performance. A host of information regarding the performance of locate operations and their environs is acquired (e.g., via improved intelligent instrumentation employed by technicians). A quality of operations (e.g., completeness, accuracy, efficiency) is assessed, corrective actions may be taken in essentially real-time as necessary, and information regarding operations and their quality assessments is archived for auditing purposes.

Abstract: Metal detectors use graphical displays offering many analysis methods and user options which were not possible before. The new graphical detector displays allow new ways to display target information that enable better methods of analyzing and viewing target data. Graphical detectors have menu structures with dozens of operating parameters which can be modified by the user. Some of these parameters are able to be changed on-the-fly without having to suspend detector operation.

Abstract: Multi-frequency buried object location system transmitters and locators are disclosed. A transmitter may generate and provide output signals to a buried object at a plurality of frequencies, which may be selected based on a connection type. Corresponding locators may simultaneously receive a plurality of magnetic field signals emitted from the buried object and generate visual and/or audible output information based at least in part on the plurality of received magnetic field signals. The visual and/or audible output may be further based on signals received from a quad-gradient antenna array.

Abstract: A method is described for use in a region which contains at least first and second in-ground cables, each of which cables includes an electrically conductive component such that, when the first cable is driven at a locating signal frequency to emit a locating signal in an electromagnetic form, the locating signal can be coupled to the second cable in a way which causes the second cable to generate a false locating signal in electromagnetic form. The locating signal is received along with the false locating signal as well as receiving a reference signal which contains the locating signal frequency impressed thereon. The locating signal is distinguished from the false locating signal based on the locating signal frequency as contained by the reference signal.

Abstract: A holistic approach to management and oversight of locate and marking operations is provided. Initial requests to perform such operations are improved, and such requests are intelligently assessed to appropriately allocate resources to perform operations. Technicians are effectively dispatched and may be provided with process guides to facilitate performance. A host of information regarding the performance of locate operations and their environs is acquired (e.g., via improved intelligent instrumentation employed by technicians). A quality of operations (e.g., completeness, accuracy, efficiency) is assessed, corrective actions may be taken in essentially real-time as necessary, and information regarding operations and their quality assessments is archived for auditing purposes.

Abstract: A device rotates at least one static magnetic field about an axis, producing a rotating magnetic dipole field, and is movable in relation to the surface of the ground. The field is periodically sensed using a receiver to produce a receiver output responsive to the field. A positional relationship between the receiver and the device is monitored using the output. In one aspect, changing the positional relationship, by moving the device nearer to a boring tool which supports the receiver, causes an increase in accuracy of depth determination. In another aspect, determination of an actual overhead position of the boring tool, and its application, are described. Use of a plurality of measurements over at least one-half revolution of each magnet is disclosed. Establishing a surface radial direction toward a boring tool and resolution of multi-valued parameters is described. Calibration techniques, as well as a three transmitter configuration are also described.

Abstract: A portable locator and method for establishing the location of the cable line in a region which includes at least one generally straight electrically conductive cable line extending across the region from which cable line a locating signal includes a first arrangement for measuring a local flux intensity of the locating signal at a first above ground point within the region with the portable locator in a particular orientation at the first above ground point. A second arrangement uses the local flux intensity to establish a cable line angular orientation which limits the possible directions to the cable line relative to the particular orientation of the portable locator at the above ground point. A third arrangement uses the measured local flux intensity to establish an actual direction of the cable line that is selected from the possible directions based on certain characteristics of the locating signal.

Abstract: A locator for locating a concealed conductor comprises a first field detector operable to detect an alternating magnetic field along a first axis parallel to a primary axis of the locator; a second field detector, displaced from the first field detector and operable to detect an alternating magnetic field along a second axis parallel to the primary axis of the locator; and a processor operable to calculate a difference between a field detected by the first detector and a field detected by the second detector, and to calculate an indication of the lateral displacement of the concealed conductor from the primary axis of the locator using the difference.

Abstract: An arrangement and an associated method are described in which a boring tool is moved through the ground within a given region along a path in which region a cable is buried. The boring tool and the cable transmit a boring tool locating signal and a cable locating signal, respectively. Intensities of the boring tool locating signal and the cable locating signal are measured along with a pitch orientation of the boring tool. Using the measured intensities and established pitch orientation, a positional relationship is determined to relative scale including at least the boring tool and the cable in the region. The positional relationship is displayed to scale in one view. The positional relationship may be determined and displayed including the forward locate point in scaled relation to the boring tool and the cable. Cable depth determination techniques are described including a two-point ground depth determination method.

Abstract: A method for detecting a change of an impedance of a magnetic field receiver of a metal detector, including: having a first network of passive components, including the impedance of the magnetic field receiver; having a second network of passive components, excluding the impedance of the magnetic field receiver; and processing a first measurement signal from a first node of the first network with a second measurement signal from a second node of the second network to detect the change in the impedance of the magnetic field receiver; wherein the first network, the second network, the first node, the second node is configured such that in an absence of an external influence which affects the impedance of the magnetic field receiver, the first measurement signal is substantially the same with the second measurement signal; and in a presence of the external influence, the first measurement signal is different from the second measurement signal.

Abstract: A system for sensing a pipe joint within a well structure bore comprises a body connectable in line with the well structure. The body has a central bore therethrough and includes a plurality of blind bores extending radially inwards from the outer surface. The system further includes at least one sleeve being locatable within one of the plurality of blind bores wherein each of the sleeves has a magnet located at an end thereof at least one sensor being locatable within one of the at least one sleeves. The at least one sensor is operable to output a signal representing the width of a metallic object located within the central bore. The system may further include a display operable to receive the output signal from the at least one sensor and to display an output to a user indicating the width of the metallic object within the central bore.

Abstract: A steering tool is movable by a drill string to form an underground bore along an intended path. A sensing arrangement of the steering tool detects its pitch and yaw orientations at a series of spaced apart positions along the bore, each position is characterized by a measured extension of the drill string. The steering tool further includes a receiver. At least one marker is positioned proximate to the intended path, for transmitting a rotating dipole field to expose a portion of the intended path to the field for reception by the receiver. The detected pitch orientation, the detected yaw orientation and the measured extension of the drill string are used in conjunction with magnetic information from the receiver to locate the steering tool. The steering tool may automatically use the magnetic information when it is available. A customized overall position determination accuracy can be provided along the intended path.

Abstract: An electrodynamic machine shaft slow roll measurement testing and remediation method that can be performed on a partially machined shaft. Upon completion of slow roll tests on a partially machined shaft the manufacturer may complete machining of shafts that successfully meet the test specification. If a partially machined shaft fails the test specification, the manufacturer at its option may attempt to remediate the shaft, so that it successfully meets slow roll specification upon re-testing. Exemplary remediation steps may include further concentricity machining to reduce mechanical runout or shaft treatment, such as by heating and/or quenching to reduce electrical runout. Partially machined shafts that fail slow roll test specifications (with or without remediation efforts) may be scrapped or otherwise recycled without, completing final machining operations.

Abstract: An improved system and method for ranging while drilling, in effect, induces a dynamic hot spot on the casing of a nearby well. The induced hot spot acts as a magnetic source that can be reliably detected from within the drillstring and in such a manner as to infer the relative position and orientation of the casing to the drillstring. At least some disclosed method embodiments employ one or more rotating magnets in the drillstring, an array of at least two magnetometers in the drillstring and one or more phase-locked loops that are used to enhance the signal to noise ratio of the magnetic signal scattered off of the casing from the rotating magnetic field. The rotating magnet or magnets may be magnetic dipoles or magnetic multipoles, and may be modulated to enable the use of multiple magnetic field sources.

Abstract: A new hybrid metal detector combines induction balance and pulse induction technologies. Target signals are generated from a transmitted wave that has both induction balance and pulse current inducing characteristics and uses pertinent sampling of the receive data. Combining the two data sources provides eddy current target identification while excluding ground permeability and remanence obscuration.

Abstract: An electronically generated locate request ticket identifying a dig area includes first image data associated with the dig area. The first image data includes one or both of: i) a marked-up image of a geographic area including the dig area, wherein the marked-up image includes at least one dig area indicator to provide an indication of the dig area; and ii) geographic information relating to the at least one dig area indicator. The locate request ticket is electronically transmitted to at least one entity associated with the locate operation. A completed locate request ticket is electronically received including second image data and/or non-image data relating to the locate operation as performed. The completed locate request ticket is electronically processed so as to provide a quality assessment of the locate operation.

Abstract: Systems, methods and apparatus for generating electronic records of locate operations and marking operations. Exemplary systems and apparatus include marking devices that generate, store and/or transmit electronic records of marking information, locate devices that generate, store and/or transmit electronic records of locate information, locate devices and marking devices that communicate with each other (and optionally with other devices or systems) to share/exchange locate information and marking information, and a combined locate and marking apparatus that constitutes an integrated device capable of various functionality germane to respective locate and marking devices, and configured for generating electronic records of both locate information and marking information. An exemplary method for analyzing and processing locate information and marking information includes a computer-implemented method for visually rendering (e.g.

Abstract: In some embodiments, apparatus and systems, as well as methods, may operate to launch a set of currents into a corresponding set of existing well casings; monitor, in a well under construction, changes in at least one of a magnetic field or an electric field perturbed by the set of currents after each one of the set is launched; and determine a location of the well under construction in relation to the set of existing well casings. In some embodiments, the activities include inducing current into a drillstring located in a well under construction; monitoring, at a set of existing well casings, changes in at least one of a magnetic field or an electric field perturbed by the current after the current is induced; and determining a location of the well under construction in relation to the set of existing well casings. Additional apparatus, systems, and methods are disclosed.

Abstract: An electronic metal detector having, a transmit coil arranged and adapted to transmit an alternating magnetic field associated with a reactive transmit coil voltage, the transmit coil being connected to transmit electronics arranged and adapted to generate a transmit signal, the transmit electronics having at least two power sources, a first power source and a second power source, wherein the first power source is adapted and arranged to connect to the transmit coil for at least a first period, and the second power source is adapted and arranged to connect to tie transmit coil for at least a second period, the said transmit electronics including at least one servo control negative feedback loop, a first servo control negative feedback loop, which is adapted and arranged to monitor a transmit coil current for at least part of the said first period, and to control at least part of the said transmit signal, the transmit electronics being adapted and arranged to control the transmit signal to produce the reactive

Abstract: The present disclosure relates to determining the attenuation of an electromagnetic signal passing through a conductive material. An antenna is provided and placed in relatively close proximity to the conductive material. An alternating current is passed through the antenna and the impedance of the antenna is measured. The attenuation is determined using the measured impedance. A single frequency measurement may be made, or multiple measurements using different frequencies may be made. Grouped parameters based on properties of the material and the frequency of the current are used to relate the coil impedance to the attenuation. A current frequency for which the ratio of the antenna's resistive part of the impedance to the angular frequency of the current is substantially insensitive to at least one of the parameters is preferred.

Abstract: A method and an apparatus provide targeted guidance for a user to locate and trace-out the path of a buried electrical cable, and to locate a cable fault along the cable. A current pulse is applied to the cable, whereby a magnetic field is generated around the cable and an acoustic signal is emitted from the cable fault. The apparatus detects and measures magnetic field information to locate the cable. The apparatus measures a time delay between detecting the magnetic signal and detecting the acoustic signal. By comparing successive time delays at successive measuring positions, a relative proximity to the cable fault is determined. The cable location information and the cable fault distance information are combined to produce a direction indication for the user. Tracing the cable layout and determining the cable fault location can be carried out in a single procedure using a single apparatus.

Abstract: A contact detection apparatus that allows faster detection and a pinch prevention apparatus equipped with such a detection apparatus are provided. The contact detection apparatus includes a first electrode (430) made of a flexible conductive material and extending throughout a contact detection range, a second electrode (440) apart from the first electrode and extending on the back side of the first electrode, and detection means for detecting contact of an object with the first electrode based on the capacitance of the first electrode. The first electrode is made of a conductive resin containing an embedded conductor.

Abstract: A primary device for inductive power transfer to a secondary device is disclosed. The primary device includes a primary coil, the primary device being configured to (i) operate in a first mode during which the primary coil transfers power through inductive coupling to the secondary device, and (ii) operate in a second mode during which a foreign object is detected. The primary device further includes a primary controller configured to operate the primary coil (i) using a first frequency during the first mode, and (ii) using a second frequency during the second mode. A method to detect a foreign object which is in proximity of an inductively coupled environment of a primary device is also disclosed.

Abstract: This invention relates to non-contact measurement methods and an apparatus for the identification of hazardous contact voltages on energized objects and surfaces. The apparatus includes an electric field sensor structured to sense an electric field and a gain amplifier electrically connected to the electric field sensor to amplify electric signals from the electric field sensor. The apparatus further includes a signal conditioning circuit adapted to process the amplified electric signals and form time-coordinated signals and a digital signal processor adapted to evaluate the time-coordinated signals and provide a user with a status of a contact voltage source by activating an appropriate status indicator.

Abstract: A detector for calculating the distortion of an electromagnetic field produced by a buried current carrying conductor comprises three antennas B, M, T. Outputs of two pairs of antennas are compared and the depth of the buried conductor is calculated using two different methods. If there is a significant difference in the two calculated depths then it is deemed that the electromagnetic field produced by the buried current carrying conductor is significantly distorted by the material in which the conductor is buried.

Abstract: At least one antenna array including three mutually orthogonal antennas each sharing a common center point senses an electromagnetic signal emitted by a buried object such as a utility line, pipe or sonde. A circuit at least partially mounted in a housing is connected to the array and determines a location of the buried object by measuring signal strength and field angles in three dimensions without having to align the antenna array relative to the buried object while eliminating nulls and false peaks. A graphical user interface (GUI) has user-friendly icons, symbols, menus, numbers and graphical and auditory representation of signal strength. A plurality of different underground objects can be simultaneously detected and their different locations can be simultaneously indicated to a user via audible sounds and/or visual images on a display.

Abstract: A computerized boring system provides real-time monitoring and control of a bore head during boring operations to prevent inadvertent damage to buried objects such as utility cables. A boring machine with a shaft, a bore head on an end of the shaft, and one or more proximity sensors for detecting underground target objects is controlled manually and by a computer control system in communication with the sensors, a programmable logic computer and/or electrical relay system providing control of rotational and longitudinal movement of the bore head in response to data generated by the sensors.