Abstract: Position measurements by a tracking system associated with a survey tool are corrected for tilt. The tracking station typically incorporates some offset from the surface across which a survey is conducted, and the offset will be subject to angular displacement as the tool tilts with respect to its normal orientation. The tracking system records the 3D position of the survey tool, with angular offset errors. In the disclosed examples, an inertial measurement unit (IMU), a dual axis inclinometer or a combination of two single axis inclinometers measures the amount of angular offset. The angular offset data is used to correct the position data, e.g. to reduce or eliminate errors caused by the angular offset, e.g. from vertical. If the tool provides measurement data, e.g. GPR readings, processing of the measurement data from the survey tool uses the corrected position data, e.g. to produce images of sub-surface features or objects.

Abstract: An apparatus for identifying a buried object using ground penetrating radar (GPR) in a system containing at least one GPR sensor, comprises a data processor for detecting spatial correlations in data received from a GPR sensor in the apparatus and an image processor capable of building a data structure corresponding to an image of the buried object from data processed by the data processor. A method for identifying a buried object using GPR in a system containing a GPR sensor comprising detecting spatial correlations in data received from the GPR sensor in the system and building a data structure corresponding to an image of the buried object from the received data.

Abstract: A ground penetrating antenna apparatus and method are provided for locating underground objects via radar, sonar, or similar methods. The apparatus includes one or more antennas that are rotatably affixed to support extensions that also rotate, but about an axis that is different from each of the antenna axes. The apparatus includes a linear propulsion mechanism, and the support extensions may be coupled to the linear propulsion mechanism via a transmission mechanism. In one embodiment, the supporting extensions rotate at a constant rate and each antenna rotates at that same constant rate but in the opposite direction.

Abstract: A method and apparatus locates buried objects in conductive soil by creating a direct current in a transmitting loop, periodically terminating the direct current in the transmitting loop to create an eddy current in the conductive soil using time domain induction, receiving a magnetic field resulting from the eddy current running through the conductive soil, and locating the buried object using the received magnetic field.

Abstract: An apparatus for identifying a buried object using ground penetrating radar (GPR) in a system containing at least one GPR sensor, comprises a data processor for detecting spatial correlations in data received from a GPR sensor in the apparatus and an image processor capable of building a data structure corresponding to an image of the buried object from data processed by the data processor. A method for identifying a buried object using GPR in a system containing a GPR sensor comprising detecting spatial correlations in data received from the GPR sensor in the system and building a data structure corresponding to an image of the buried object from the received data.

Abstract: An apparatus and method for combining a survey measurement dataset and a position dataset into a single dataset containing both measurement and position data is disclosed. The survey measurement data may be obtained from a ground penetrating radar, an inductometer, a magnetometer, or an optical camera. Positioning information is collected and merged with the survey information so that the position of the survey tool is known at each data point. Also provided are channel-equalization filters, spiking deconvolution filters, and frame filters that can be used in conjunction with the positioning information to enhance the quality of the images obtained from the data collected by the survey tool.

Abstract: We describe a system for displaying buried utilities to the operator of an excavator. The display is based on 3D images of the subsurface obtained from advanced locating methods. As the excavator moves, the display changes so that it remains centered on the region near the bucket where the buried pipes are in danger of being broken.

Abstract: An apparatus for identifying a buried object using ground penetrating radar (GPR) in a system containing at least one GPR sensor, comprises a data processor for detecting spatial correlations in data received from a GPR sensor in the apparatus and an image processor capable of building a data structure corresponding to an image of the buried object from data processed by the data processor. A method for identifying a buried object using GPR in a system containing a GPR sensor comprising detecting spatial correlations in data received from the GPR sensor in the system and building a data structure corresponding to an image of the buried object from the received data.

Abstract: An apparatus for locating a target object using parametric inversion employs a signal injector capable of injecting a signal into the target object, wherein at least a portion of the target object is buried, a magnetic field receiver, a matching processor for matching to a magnetic field received by the magnetic field receiver a parametric magnetic field distribution model corresponding to the target object and at least one other object, and a locating processor for locating the target object using parameters from the parametric magnetic field distribution model.

Abstract: A method and apparatus for detecting and locating leaks in buried pipes is disclosed in which ground penetrating radar, induction, acoustic, and vacuum excavation systems are selected based on soil conditions and then employed in selected combinations. The conductivity and wave speed of the soil are used in the selection process and in the process of detecting and locating a leak based on the measurements obtained from the selected combination of detection systems.

Abstract: An apparatus and method for combining a survey measurement dataset and a position dataset into a single dataset containing both measurement and position data is disclosed. The survey measurement data may be obtained from a ground penetrating radar, an inductometer, a magnetometer, or an optical camera. Positioning information is collected and merged with the survey information so that the position of the survey tool is known at each data point. Also provided are channel-equalization filters, spiking deconvolution filters, and frame filters that can be used in conjunction with the positioning information to enhance the quality of the images obtained from the data collected by the survey tool.

Abstract: An apparatus and method for locating subsurface objects using an induction array system is presented. The system uses a movable array that contains two or more spatially separated receivers and one or more spatially separated transmitters. The spatial separation permits the array to detect objects at varying depths with a single pass of the device over the surface area under investigation. If multiple transmitters are used, then they may either be operated simultaneously at different frequencies or sequentially at the same frequency. The spacing between receiver and transmitter elements in the induction array may be uniform or non-uniform.

Abstract: We describe a system for displaying buried utilities to the operator of an excavator. The display is based on 3D images of the subsurface obtained from advanced locating methods. As the excavator moves, the display changes so that it remains centered on the region near the bucket where the buried pipes are in danger of being broken.

Abstract: A ground penetrating antenna apparatus and method are provided for locating underground objects via radar, sonar, or similar methods. The apparatus includes one or more antennas that are rotatably affixed to support extensions that also rotate, but about an axis that is different from each of the antenna axes. The apparatus includes a linear propulsion mechanism, and the support extensions may be coupled to the linear propulsion mechanism via a transmission mechanism. In one embodiment, the supporting extensions rotate at a constant rate and each antenna rotates at that same constant rate but in the opposite direction.

Abstract: A ground penetrating antenna apparatus and method are provided for locating underground objects via radar, sonar, or similar methods. The apparatus includes one or more antennas that are rotatably affixed to support extensions that also rotate, but about an axis that is different from each of the antenna axes. The apparatus includes a linear propulsion mechanism, and the support extensions may be coupled to the linear propulsion mechanism via a transmission mechanism. In one embodiment, the supporting extensions rotate at a constant rate and each antenna rotates at that same constant rate but in the opposite direction.