Abstract: A precise line locator is presented that provides precise line location. The locator includes a housing; a wand attached to the housing, the wand including an array of low frequency antennas arranged along the wand, the array of low frequency antennas defining an electromagnetic locate axis of the line locator system; a real-time kinematic (RTK) Global Navigation Satellite (GNSS) antenna attached to the housing; a user interface positioned in the housing; and a processing circuit coupled to the array of low frequency antennas, the RTK GNSS antenna, and the user interface, wherein the underground line locator determines locate data of the underground line based on signals from the array of low frequency antennas and determines a precise position of the underground line locator from the RTK GNSS antenna.

Abstract: In accordance with some embodiments, an antenna is presented. In some embodiments, an antenna includes a plurality of coil arrays arranged along a core; and a switch coupled to each of the plurality of coil arrays, the switch connecting the plurality of coil arrays in one of a plurality of configurations in response to one or more sensitivity control signal.

Abstract: A transmitter and receiver for performing a signal select algorithm are provided. A transmitter for providing a signal on a line to be located includes at least one direct digital synthesizer, the direct digital synthesizer producing two component frequencies in response to an input square wave signal; and a feedback loop providing the input square wave.

Abstract: A system and method of for underground line location using a view-in-the-ground indicator includes a display. The display includes a view-in-the-ground indicator configured to indicate left-right position information and orientation information associated with a plurality of underground lines using a corresponding plurality of needles. The plurality of needles are concurrently displayed and are distinguishable from one another. Each of the plurality of needles has a variable horizontal position that indicates the left-right position information and a variable orientation that indicates the orientation information. In some embodiments, the plurality of needles are distinguishable from one another based on a color coding scheme. In some embodiments, the color coding scheme of the plurality of needles matches a color coding scheme of a plurality of feeder cables coupled to the plurality of underground lines.

Abstract: A system and method of for estimating the depth of a marker may include a marker locator. The marker locator may include a first transmitter that generates a first activation signal, second transmitter that generates a second activation signal, a receiver that detects first and second response signals, and a processor that determines a depth of a marker based on the first and second response signals. The first transmitter is located at a first position, and the second transmitter is located at a second position apart from the first position. The first and second response signals respectively correspond to the first and second activation signals. The processor is coupled to the receiver. According to some embodiments, the first and second activation signals and the first and second response signals may be separated by time division multiplexing.

Abstract: A system and method of for underground line location using motion based responsiveness includes an underground line locator. The underground line locator includes a receiver generating raw measurement data based on a location of an underground line relative to the receiver, a motion sensor generating motion data based on a state of motion of the underground line locator, a processor coupled to the receiver and the motion sensor, and a display coupled to the processor. The processor determines a measurement signal based on the raw measurement data. A responsiveness of the measurement signal to the raw measurement data is based on the motion data. The display shows a representation of the measurement signal. In one or more embodiments, the measurement signal may be determined using a primary signal detector that adaptively filters the raw measurement data using an adaptive band-pass filter.

Abstract: In some embodiments, a camera skid is presented. The camera skid includes a body into which a camera can be inserted; and a front portion received into the body, the front portion including a lip that contacts a face of the camera.

Abstract: In accordance with some embodiments, a method and apparatus for providing both a low-pass filter value and a high-pass filter value is presented. The combined filter receives an input value into a half-band finite impulse response (FIR) filter with an odd number of taps labeled 0 through N with corresponding filter coefficients labeled 0 through N where odd numbered filter coefficients are zero, the FIR filter providing a filter value. The median value from the FIR filter is digitally shifted to provide a half median value. The half median value is added to the filter value to provide the low-pass filter value and is subtracted from the filter value to provide the high-pass filter value.

Abstract: An apparatus that uses harmonics of the power line frequency at which electrical power is distributed is presented. The apparatus includes a sensor antenna to detect an electromagnetic field produced by a cable. The output of the sensor is fed to a mixer together with a signal from a sine wave generator at less than the fundamental power frequency to frequency shift the signals from the sensor. The mixed output is then amplified to provide an audible output. A single comb filter receives signals from the mixer and outputs a filtered signal removing non-harmonic frequencies but preferably passing both odd and even harmonics. The output of the comb filter is then integrated at and displayed to indicate the detection of a cable based on the filtered signal.

Abstract: A detection apparatus with a self-test is presented. A detection apparatus such as a cable locator has an array of sensors in the form of ferrite antennas to detect an electromagnetic field produced by an object such as a buried cable. The signals are amplified, digitized and fed to a processing unit that outputs a detection signal to a display to indicate the detection of a cable. A programmable signal generator outputs a self-test signal via a voltage-current converter that is used to check the balance between the sensors. The self-test signal is directly coupled into each of the sensors through a wired connection and the processing unit uses the self-test signal to accurately determine the magnitude and phase balance of the sensors. The magnitude and phase data may be used to calibrate the instrument, apply data corrections or flag errors.

Abstract: A system and method of for underground line location includes an underground line locator. The underground line locator includes an antenna system configured to generate signal information based on a proximity and an orientation of an underground line relative to the antenna system, a positioning system configured to generate position information based on the location of the underground line locator, and a controller coupled to the antenna system and the positioning system. The controller is configured to receive the signal information from the antenna system and the positioning information from the positioning system.

Abstract: A signal generator that provides signals for multiple outputs is presented. In some embodiments, a signal generator can include switching circuitry that is coupled to provide a signal to an active output of a plurality of outputs in response to control signals; a driver that provides the signal to the switching circuitry, the signal being at a frequency appropriate for the active output; and a logic that provides the control signals to the switching circuitry and provides a waveform to the driver, the waveform having the frequency appropriate for the active output, the control signals indicating which of the plurality of outputs is the active output.

Abstract: In accordance with some embodiments, a system includes a line locator and a device configured to communicate through an internet with a server also coupled to the internet. Furthermore, a plurality of line locate transmitters are distributed geographically and configured to communicate through the internet with the server. The server operates to activate one of the plurality of line locate transmitters based on a geographic location of the device.

Abstract: A detection apparatus with a self-test is presented. A detection apparatus such as a cable locator has an array of sensors in the form of ferrite antennas to detect an electromagnetic field produced by an object such as a buried cable. The signals are amplified, digitized and fed to a processing unit that outputs a detection signal to a display to indicate the detection of a cable. A programmable signal generator outputs a self-test signal via a voltage-current converter that is used to check the balance between the sensors. The self-test signal is directly coupled into each of the sensors through a wired connection and the processing unit uses the self-test signal to accurately determine the magnitude and phase balance of the sensors. The magnitude and phase data may be used to calibrate the instrument, apply data corrections or flag errors.

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 system and method of for estimating the depth of a marker may include a marker locator. The marker locator may include a first transmitter that generates a first activation signal, second transmitter that generates a second activation signal, a receiver that detects first and second response signals, and a processor that determines a depth of a marker based on the first and second response signals. The first transmitter is located at a first position, and the second transmitter is located at a second position apart from the first position. The first and second response signals respectively correspond to the first and second activation signals. The processor is coupled to the receiver. According to some embodiments, the first and second activation signals and the first and second response signals may be separated by time division multiplexing.

Abstract: A transmitter and receiver for performing a signal select algorithm are provided. A transmitter for providing a signal on a line to be located includes at least one direct digital synthesizer, the direct digital synthesizer producing two component frequencies in response to an input square wave signal; and a feedback loop providing the input square wave.

Abstract: A system for determining the position of an underground sonde transmitter is disclosed. In some embodiments, the system measures a set of complex electromagnetic field magnitude and phase strengths at one or more positions while traversing a target sonde path at any angle using one or more electromagnetic coil sensors, models a set of expected complex electromagnetic strengths of a hypothetical sonde at the positions for one or more of the electromagnetic coil sensors, the set of expected electromagnetic field values corresponding to a model for the target sonde, and estimates parameters related to the target sonde based on the residual error between the measured set of complex electromagnetic field values and the modeled set of expected complex electromagnetic field strengths. A final estimated parameter set is determined after the residual error has converged to a minimum tolerance to indicate the sonde transmitter position.

Abstract: A line locator includes a signal detector to detect signals from an underground line; an error modeler that models a phase error in the signal from neighboring underground lines; and an enhanced electromagnetic field modeler that provides a location of the underground line based on the signal and a result from the error modeler.

Abstract: A method for determining the location of underground cables and pipes is disclosed. In some embodiments, the method includes measuring a set of electromagnetic field magnitudes and phases at a plurality of positions while traversing a target line parallelly using 3D electromagnetic coil sensors, the 3D electromagnetic coil sensors being orthogonally oriented to the target line, modeling a set of expected complex electromagnetic field magnitudes of a single underground conductor at each of the positions to form a set of values corresponding to a set of individual models for the target line, determining which of the set of individuals models is a best model, determining confidence information at each of the positions based on a comparison between the measured set of complex electromagnetic magnitudes and phases and the best model, and determining parameters at each of positions related to the target line from the best model.