Publications by authors named "Nicole Metje"

Article Synopsis
  • A new quantum gravity gradient sensor has been developed to improve the precision of gravity measurements in geophysics, particularly for applications in engineering and climate research.
  • The sensor significantly reduces vibrational noise and achieves high statistical accuracy, allowing for detailed underground surveys, such as detecting a 2-meter tunnel with a high signal-to-noise ratio.
  • Its capabilities can be applied to diverse fields, including aquifer mapping, archaeology, soil property analysis, and assessing construction site conditions, enhancing our understanding of subsurface features.
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We address the problem of accurately locating buried utility segments by fusing data from multiple sensors using a novel Marching-Cross-Section (MCS) algorithm. Five types of sensors are used in this work: Ground Penetrating Radar (GPR), Passive Magnetic Fields (PMF), Magnetic Gradiometer (MG), Low Frequency Electromagnetic Fields (LFEM) and Vibro-Acoustics (VA). As part of the MCS algorithm, a novel formulation of the extended Kalman Filter (EKF) is proposed for marching existing utility tracks from a scan cross-section (scs) to the next one; novel rules for initializing utilities based on hypothesized detections on the first scs and for associating predicted utility tracks with hypothesized detections in the following scss are introduced.

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Several millions of kilometres of pipes and cables are buried beneath our streets in the UK. As they are not visible and easily accessible, the monitoring of their integrity as well as the quality of their contents is a challenge. Any information of these properties aids the utility owners in their planning and management of their maintenance regime.

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