Abstract: An artificial toolface reference system includes a power supply providing current to a ground lead and a reference lead. A ground point is coupled to the ground lead and in electrical connection with the ground. A reference wellbore includes a reference conductor in electrical connection with the ground. The reference conductor is in electrical connection with the reference lead. The reference conductor includes an uninsulated portion and an insulated portion having an insulating layer positioned thereabout. A guidance sensor positioned outside the reference wellbore includes at least one magnetometer. The power supply may be used to provide a current through the reference conductor, into the ground through the uninsulated portion, and the ground point such that a reference magnetic field is generated along the reference conductor. The guidance sensor may measure the reference magnetic field with a magnetometer. An artificial magnetic toolface may be calculated therefrom.

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: The invention concerns structural integrity assessment apparatus for determining stress concentration zones in a structure, such as a pipeline. The apparatus allows particularly to detect defects in buried pipelines using magnetometric surveying where anomalies in the magnetic field around the pipelines are detected. The apparatus has a plurality of triaxial magnetic field sensors, each sensor being arranged to measure magnetic field components in a plurality of directions. A support is provided to maintain said sensors in a predetermined relative spacing and orientation. The support is moveable relative to a structure under assessment in use and may be portable. Three or more magnetic field sensors are provided which may be arranged in a linear, two-dimensional or three-dimensional array. The apparatus may include position determining means, such as a global positioning system (GPS), so that stress concentration zones can be located on the structure.

Abstract: The invention relates to a method for operating a self-propelled lawnmower, which is moved on a surface (20). The surface (20) is surrounded by a border delimitation wire (21) on which electrical signals (16, 116) are transmitted. The transmitted signal (16) is received by at least one receiving coil (17, 18) in the lawnmower (2) and induces a reception signal (EI), which is evaluated in an evaluation unit (19). The evaluation unit (19) emits an output signal to a control unit (13), on the basis of which the control unit (13) controls the direction of travel of the lawnmower (2). In order to guarantee a safe operation of the lawnmower even in range of electromagnetic interference fields, the invention provides that the electrical signal (16, 116) is transmitted with a predetermined pattern (M). The evaluation unit (19) of the lawnmower (2) processes the reception signal (EI) as a pattern, wherein the pattern (M?) of the reception signal (EI) is compared to a predetermined reference pattern (RM).

Abstract: A system and method of identifying changes utilizing radio frequency polarization includes receiving a reflected and/or transmitted polarized radio frequency signal at a receiver, filtering, amplifying and conditioning the received signal, converting the received signal from an analog format to a digital format, processing the digital signal to elicit a polarization mode dispersion feature of the received signal, and comparing the polarization mode dispersion features to a known calibration to detect a change in a characteristic of the target object.

Abstract: A locating device includes an AC voltage locating apparatus. The AC voltage locating apparatus has a first receiving apparatus configured to receive a first coupling signal from a locatable object. The AC voltage locating apparatus also has at least a second receiving apparatus configured to receive at least a second coupling signal from the locatable object. The AC voltage locating apparatus also has at least a first amplifier circuit configured to amplify a difference of the first coupling signal relative to a reference signal in at least one operating. The AC voltage locating apparatus also has at least a second amplifier circuit configured to amplify a difference of the first coupling signal and the second coupling signal in at least one operating state.

Abstract: Optical ground tracking apparatus for use with buried object locators or other instruments or devices are disclosed. In one embodiment, a buried object locator includes a locator module disposed in our coupled to the housing to sense a buried object based on emitted magnetic fields, and a surface tracking module for determining motion information of the buried object locator based on light reflected from a tracking surface.

Abstract: For testing a transformer (20) the transformer (20) is emulated by an equivalent circuit (30) and an accuracy of the transformer (20) relative to the equivalent circuit (30) is determined by evaluating a test response of the transformer (20) and is then automatically converted to an operating condition-related accuracy of the transformer (20).

Abstract: A method for transmitting data from a downhole tool to a surface location includes measuring a property in a wellbore using a downhole tool in the wellbore. A casing is positioned within the wellbore, and the downhole tool is positioned below at least a portion of the casing. A digital frame is generated using the downhole tool. The digital frame includes information corresponding to the property. The digital frame is encoded to superpose the information on a carrier signal. The carrier signal is converted to a voltage differential that is generated across an insulation layer in the downhole tool. The voltage differential causes a current to flow through a subterranean formation and into the casing above the downhole tool. A magnetic flux generated by the current flowing through the casing is detected using a sensor that is positioned at least partially within or at least partially around the casing.

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: The present invention relates to a system (200) and method for determining a relation between a first scene and a second scene. The method comprises the steps of generating at least one sensor image of a first scene with at least one sensor; accessing information related to at least one second scene, said second scene encompassing said first scene, and matching the sensor image with the second scene to map the sensor image onto the second scene. The step of accessing information related to the at least one second scene comprises accessing a 3D map comprising geocoded 3D coordinate data. The mapping involves associating geocoding information to a plurality of positions in the sensor image based on the coordinate data of the second scene.

Abstract: A laser diode firing circuit for a light detection and ranging (LIDAR) device that includes an inductively coupled feedback system is disclosed. The firing circuit includes a laser diode coupled in series with a transistor, such that current through the laser diode is controlled by the transistor. The laser diode is configured to emit a pulse of light in response to current flowing through the laser diode. A feedback loop is positioned to be inductively coupled to a current path of the firing circuit that includes the laser diode. As such, a change in current flowing through the laser diode induces a voltage in the feedback loop. A change in voltage across the leads of the feedback loop can be detected and the timing of the voltage change can be used to determine the time that current begins flowing through the laser diode.

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: Multiple elements of information relating to a locate and marking operation are integrated so as to provide an enhanced positive response to one or more entities associated with requesting the locate and marking operation (e.g., an excavator, a home owner or property owner, other contractor). The locate and marking operation is performed by a locate technician in response to at least one locate request ticket by applying at least one physical locate mark on ground, pavement, or other surface to indicate a presence or an absence of at least one underground facility within a dig area, wherein at least a portion of the dig area is planned to be excavated or disturbed by an excavator during excavation activities.

Abstract: A DC arc fault detection module includes a current detecting section having at least one output, wherein the current detecting section is structured to determine whether at least one signal based on a current measured from a DC supply line exceeds at least one corresponding predetermined threshold level and cause the at least one output to indicate that the threshold level has been exceeded. The module also includes a processing device structured to: (i) receive the at least one output, (ii) determine whether an arc fault in the DC electrical system has occurred based on at least the at least one output, (iii) determine an estimation of background noise based on at least one signal indicative of a current on the DC supply line, and (iv) adjust the at least one corresponding predetermined threshold level based on the estimation of background noise.

Abstract: A portable camera controller for use with a pipe inspection system is disclosed. The controller may include an onboard display, USB ports, wireless capability, and a built-in transmitter for energizing a pipe-inspection cable for tracing purposes. The camera controller may be configured to support auto-logging and automatic report generation of pipe inspection operations and associated locating operations. The camera controller may be self-grounding using conductive and/or capacitive grounding circuits and an associated transmitter may be used without a separate grounding stake through use of the conductive and/or capacitive grounding circuits.

Abstract: A boring tool is movable through the ground. A transmitter supported by the boring tool transmits an electromagnetic homing signal. A portable device monitors the electromagnetic homing signal and receives the electromagnetic homing signal in a homing mode for guiding the boring tool to a target position. A processor generates steering commands for guiding the boring tool based on a bore plan in a steering mode such that at least some positional error is introduced without using the electromagnetic homing signal. Switching from the steering mode to the homing mode is based on monitoring of the electromagnetic homing signal as the boring tool approaches the portable device to then guide the boring tool to the target position location in compensation for the positional error. Intermediate target positions are described as well as guiding the boring tool based on the homing signal so long as the portable device receives the signal.

Abstract: Integrated buried utility locator systems, including a locator including a marker device excitation transmitter a buried utility locator along with one or more marker devices, are disclosed. In operation a marker device excitation signal is sent from the locator at least partially simultaneously to receiving and processing a buried utility signal.

Abstract: A line locator system that includes a metal detector is disclosed. In accordance with some embodiments of the invention, the line locator system includes a digital signal processor in a housing; a line locator portion mounted in the housing and coupled to the digital signal processor; and an active metal detector mounted in the housing and coupled to the digital signal processor.

Abstract: A ground tracking apparatus for connection to a locator or other measurement device and configured to determine position, motion, and/or orientation information is disclosed. The ground tracking apparatus may include a ground follower assembly including one or more wheels, which may be detachably coupled to a buried object locator system to capture three-dimensional positional and orientation information during a locate process, as well as provide output data or information to be integrated with maps, photographs, drawings, or other data or information.

Abstract: A docking station to dock locating equipment (e.g., marking devices, locate devices, combined locate and marking devices) may be communicatively coupled to and/or equipped with a mobile/portable device (e.g., a mobile phone, personal digital assistant or other portable computing device) that provides processing, electronic storage, electronic display, user interface, communication facilities and/or other functionality (e.g., GPS-enabled functionality) for the docking station. A mobile/portable device may be mechanically and/or electrically coupled to the docking station. The mobile/portable device may provide redundant, shared and/or backup functionality for the docking station to enhance robustness. In one example, the mobile/portable device itself serves as a docking station for the locating equipment.

Abstract: A method of locating buried objects using a locator having at least one antenna array including three mutually orthogonal antennas each sharing a common center point includes simultaneously determining a plurality of magnetic fields associated with a plurality of different electromagnetic signals and providing a visual indication of the determined magnetic fields on a display of the locator.

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: Multiple elements of information relating to a locate and marking operation are integrated so as to provide an enhanced positive response to one or more entities associated with requesting the locate and marking operation (e.g., an excavator, a home owner or property owner, other contractor). The locate and marking operation is performed by a locate technician in response to at least one locate request ticket by applying at least one physical locate mark on ground, pavement, or other surface to indicate a presence or an absence of at least one underground facility within a dig area, wherein at least a portion of the dig area is planned to be excavated or disturbed by an excavator during excavation activities.

Abstract: A hand-held locating device for locating locatable objects includes a computational unit. The computational unit includes a first locating apparatus and at least one second locating apparatus. The first location apparatus is configured to locate a first subset of the locatable objects in a first locating region. The at least second locating apparatus is configured to locate a second subset of the locatable objects in a second locating region. The computational unit is configured to determine at least one piece of locating information for at least one locatable object of the locatable objects on the basis of a first locating result from the first locating apparatus and a second locating result from the second locating apparatus.

Abstract: The invention concerns a method for detecting buried services by electromagnetic means with introducing an artificially generated electrical detection signal indirectly via soil to the buried service, detecting an electromagnetic field originating from the introduced underground detection signal, which is preferably following along the buried services, by a mobile detection unit above ground, and determining the proximity of the structure to the detection unit according to the detected electromagnetic field of the detection signal. Therein, the soil conducted detection signal is supplied via a mains socket.

Abstract: An electromagnetic gradiometer (EMG) survey kit includes a lightweight man-carry boom about ten feet long. Matched magnetic dipole antennas are attached at each end and connected to a differential EMG receiver able to make measurements in the picoTelsa range. A pair of staging tripods allow the man-carry boom to be prepared for field use and assist the user in positioning themselves under a shoulder sling. An air core transmitter loop antenna and a low frequency square wave generator are spotted nearby a survey on the ground surface. Its emissions will illuminate any underground conductive structures with primary electric field waves. These in turn will reradiate near field magnetic waves that can be detected by the EMG receiver while walking around in a search area on the ground surface. GPS navigation receivers are used to locate and log the changing positions of the EMG receiver and stationary loop transmitter.

Abstract: There is provided an apparatus, including: an arrangement that includes at least one pair of oppositely directed, spaced apart, radiating-capable elements along a common axis, each of said elements being hollow with internal space, and being slotted throughout its entire extent; a first circuitry coupled to said arrangement and being configured to sense an electric field projection along said axis and to convey it to a first feeding terminal; and a second circuitry coupled to at least one slot of said arrangement configured to sense a magnetic field's projection along said axis and to convey it to a first feeding terminal. The apparatus being further configured to resolve a polarization vector of incoming wavefront propagating in an orthogonal direction to said common axis based on at least said sensed electric field projection and said magnetic field projection.

Abstract: Portable locators for detecting a buried object characterized by an electromagnetic (EM) field emission are disclosed. A locator may include a magnetic field sensor array and associated processing circuitry. A locator may further include a camera and image or video processing circuitry to process images or video received from the camera. A locator may further include a user-reconfigurable user interface (UI).

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 tone detection arrangement and method decodes an incoming data stream that is received in sequential bit times and which contains at least one tone that is selectively present for the duration each bit time. Each one of a plurality of digital filters is tuned for detecting the tone over a filter interval. The filters are operable in timed relation to one another.

Abstract: Disclosed is an underwater exploration system using a multi-joint underwater robot having a novel complex movement concept in which the multi-joint underwater robot moves through walking or swimming with multi-joint legs closely to a seafloor, differently from a conventional underwater robot to obtain a thrust through a propeller scheme. The underwater exploration system includes the multi-joint underwater robot having the complex movement function according, a depressor, and a mother ship to store data of an underwater state transmitted from the multi-joint underwater robot and to monitor and control a movement direction of the multi-joint underwater robot. The depressor is connected to the mother ship through a primary cable, the multi-joint underwater robot is connected to the depressor through a second cable, and resistance force of the primary cable is applied to the depressor without being transmitted to the multi-joint underwater robot.

Abstract: A locator system for locating buried utilities such as conduits, cables, pipes or wires incorporates image-capturing and position and orientation measuring devices such as magnetic compass, accelerometers, gyros, GPS, and DGPS. The system may include other sensors such as gas concentration sensors. The system associates images captured during the locate process with buried utility position data and the other sensor data. These data and images may be further associated with terrain images from satellites or aerial photography to provide a highly precision map and database of buried utility locations and visual images of the burial site. Information so obtained may be transferred to a hand-held personal communication device (such as a smart phone) capable of displaying an augmented or virtual reality display showing the location of buried utilities in combination with photo-images and/or terrain maps.

Abstract: A transmitter is powered by a regulated battery voltage and is installable in one of a plurality of different housings, each housing is characterized by a different design and each can form part of an inground tool for performing an inground operation in which a drill string extends from a drill rig to the inground tool. An antenna driver drives an antenna based on the regulated voltage to emanate an electromagnetic signal for remote reception. A controller limits power consumption from the regulated voltage so as not to exceed a power consumption threshold, irrespective of installation of the transmitter in any one of the housings when the transmitter would otherwise exhibit a different power consumption for each housing design. A corresponding method is described. Features relating to power consumption threshold modification based on temperature as well as mechanical shock and vibration are described.

Abstract: A locating device for determining a distance of an RFID tag with respect to an interface between two media comprising an inductive coupling antenna and a sensor for determining a distance between the antenna and the interface. There is an energizing circuit configured to energize the antenna to generate an electromagnetic field with various successive amplitude values and a detection device for detecting an electromagnetic field response from the RFID tag. There is a processing circuit configured to determine several pairs of information, each pair including: a distance between the antenna and the interface and a minimum electromagnetic field value detected by the detection device from the RFID tag at the determined distance between the antenna and the interface. The processing circuit also evaluates the distance between the RFID tag and the interface as a function of the several pairs.

Abstract: A prestored database showing a correspondence of ? (depth)/?HcJ (coercivity increment) and a prestored database showing a correspondence of Dy introduction amount/?HcJ are used to obtain distribution of an introduction amount in a magnet from shape information of the magnet and information of a Dy introduction face and compute distribution of ?HcJ in the magnet from the distribution of a Dy introduction amount. Regarding a magnet having a coercivity that is distributed non-uniformly, a J/H curve is computed using the computed distribution of ?HcJ, and a demagnetizing factor at a predetermined temperature (100° C.) is computed using a temperature coefficient.

Abstract: A measuring device for detecting a conductor that carries alternating voltage, includes a voltage source configured to produce two phase-shifted alternating voltages, two complex impedance elements having first connections, which are connected to the alternating voltages, and second connections, which are connected to each other and to which a differential voltage is applied, and a control device configured to control the alternating voltages in such a way that a component of the differential voltage synchronous with the alternating voltages is minimized in magnitude. The control device is configured to detect the conductor if a ratio of the alternating voltages does not correspond to a ratio of the complex impedance elements in the absence of the conductor. The second complex impedance element is changeable with a control voltage. A probe is configured to provide the control voltage as a function of an alternating electromagnetic field induced by the conductor.

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: A hearing aid (100) comprises first wireless link means configured to receive a first data signal using a first carrier frequency and second wireless link means configured to receive a second data signal using a second carrier frequency and wherein a first electrical antenna of the first wireless link means also forms part of a first band pass filter of the second wireless link means. The invention provides a hearing aid, a binaural hearing aid system and a method of receiving a first and second wireless signal.

Abstract: A cable locating system includes a transmitter for generating a locating signal frequency for coupling onto a first cable and for transmitting a reference signal, which includes the locating signal frequency modulated on the reference signal. A second cable emits a false locating signal. A receiver distinguishes the locating signal from a false locating signal based on a modulation envelope of the reference signal as compared to the locating signal and the false locating signal.

Abstract: A cooperative source electromagnetic induction (EMI) device includes: a transmitter configured to generate a time-varying primary magnetic field in the vicinity of a target object, which magnetic field inductively couples with the target object to generate a target object secondary magnetic field; and a cooperative source to which the primary magnetic field is also inductively coupled, generating one or more respective cooperative source secondary magnetic fields. The target object and the cooperative source are inductively coupled via the target object secondary magnetic field and the cooperative source secondary magnetic field. The device includes a receiver configured to measure a composite inductive response, which comprises the inductive coupling of the target object and the cooperative source.

Abstract: A stepped-frequency radar signal is transmitted through a barrier. A transmitter of the stepped-frequency radar is on a first side of the barrier, a first object is on a second side of the barrier, and a second object that is distinct from the first object is on the second side of the barrier. A signal including a reflection of the transmitted signal from the first object and a reflection of the transmitted signal from the second object is sensed. The sensed signal is analyzed to determine that a first detection is associated with the first object and a second detection is associated with a second object.

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 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: A retrieving device for retrieving an object may be provided. The retrieving device may include a retriever pole that may include a scooping device positioned at one end of the retriever pole. The scooping device may be configured to retrieve the object when positioned over the object. Additionally, the retrieving device may include a camera configured to record image data of an area within a viewing range of the camera and image data associated with the object. The retrieving device may also include a monitor positionable at the other end of the retrieving pole, which may be electrically coupled to the camera via an insulated electrical wire. The monitor may display the image data of the area and the image data associated with the object recorded by the camera. Furthermore, the retrieving device may include a power source that may be electrically coupled to the monitor and the camera.

Abstract: A near field antenna adapted to an object detecting device, for sensing a plurality of units under test of at least an object under test. The near field antenna comprises a periodic guided-wave structure, a metallic reflection portion and at least two near field magnetic coupling antennas. The periodic guided-wave structure disposed below the object under test has a plurality of conductive units periodically arranged on a first plane. The metallic reflection portion is disposed under the periodic guided-wave structure to form an enclosed space. The near field magnetic coupling antennas are disposed on a second plane parallel to the periodic guided-wave structure, and are located in the enclosed space. The feed point and the ground point of each near field magnetic coupling antenna are fed by a coaxial cable with a feeding direction parallel to the periodically arranged conductive units.

Abstract: A metal detector has a motion sensor such as an accelerometer to determine direction, speed, duration and acceleration of search loop motion. The search loop motion information from the motion sensor is utilized in mode selection, signal processing, target analysis, and information display.

Abstract: An apparatus that includes two non-coinciding arrangements disposed in an two axes Cartesian coordinate system such that each arrangement having a non-zero projection on a respective axis from among the two axes. Each one of the arrangements includes a pair of oppositely directed, spaced apart, co-axial radiating-capable elements, each of the elements being hollow with internal space, and being slotted throughout its entire extent. A first circuitry coupled to the arrangement and being configured to sense an electric field projection along the axis and to convey it to a first feeding terminal. A second circuitry coupled to a slot of the arrangement and being configured to sense a magnetic field's projection along said axis and to convey it to a first feeding terminal.

Abstract: According to one aspect of the present disclosure, an induction-based reference point locator is provided. The locator includes transmitter locatable at a position on a first side of a structure, the transmitter configured to generate an alternating magnetic field at a desired frequency; and a receiver locatable on a second side of the structure opposite the first side, the receiver configured to detect the magnetic field and provide a directional indication to the position of the transmitter relative to the second side of the structure.

Abstract: The invention relates to a method for localizing a drilling device of an earth drilling apparatus, wherein a localization signal is emitted by the drilling device, said signal being received by an external receiver and evaluated for determining the position of the drilling device, wherein an output signal, which is converted into the localization signal, is fed to the drilling device via a connection line, which is connected to the drilling device.