{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,23]],"date-time":"2026-01-23T00:29:34Z","timestamp":1769128174579,"version":"3.49.0"},"reference-count":85,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2019,11,1]],"date-time":"2019-11-01T00:00:00Z","timestamp":1572566400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001659","name":"Deutsche Forschungsgemeinschaft","doi-asserted-by":"publisher","award":["SFB-TR32"],"award-info":[{"award-number":["SFB-TR32"]}],"id":[{"id":"10.13039\/501100001659","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Multi-coil electromagnetic induction (EMI) systems induce magnetic fields below and above the subsurface. The resulting magnetic field is measured at multiple coils increasingly separated from the transmitter in a rigid boom. This field relates to the subsurface apparent electrical conductivity (\u03c3a), and \u03c3a represents an average value for the depth range investigated with a specific coil separation and orientation. Multi-coil EMI data can be inverted to obtain layered bulk electrical conductivity models. However, above-ground stationary influences alter the signal and the inversion results can be unreliable. This study proposes an improved data processing chain, including EMI data calibration, conversion, and inversion. For the calibration of \u03c3a, three direct current resistivity techniques are compared: Electrical resistivity tomography with Dipole-Dipole and Schlumberger electrode arrays and vertical electrical soundings. All three methods obtained robust calibration results. The Dipole-Dipole-based calibration proved stable upon testing on different soil types. To further improve accuracy, we propose a non-linear exact EMI conversion to convert the magnetic field to \u03c3a. The complete processing workflow provides accurate and quantitative EMI data and the inversions reliable estimates of the intrinsic electrical conductivities. This improves the ability to combine EMI with, e.g., remote sensing,\u00a0and the use of EMI for monitoring purposes.<\/jats:p>","DOI":"10.3390\/s19214753","type":"journal-article","created":{"date-parts":[[2019,11,1]],"date-time":"2019-11-01T12:30:50Z","timestamp":1572611450000},"page":"4753","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":34,"title":["Calibration, Conversion, and Quantitative Multi-Layer Inversion of Multi-Coil Rigid-Boom Electromagnetic Induction Data"],"prefix":"10.3390","volume":"19","author":[{"given":"Christian","family":"von Hebel","sequence":"first","affiliation":[{"name":"Institute of Bio- and Geoscience, Agrosphere (IBG-3), Forschungszentrum J\u00fclich GmbH, 52428 J\u00fclich, Germany"},{"name":"Centre for High-Performance Scientific Computing in Terrestrial Systems (TerrSys), Forschungszentrum J\u00fclich GmbH, 52428 J\u00fclich, Germany"}]},{"given":"Jan","family":"van der Kruk","sequence":"additional","affiliation":[{"name":"Institute of Bio- and Geoscience, Agrosphere (IBG-3), Forschungszentrum J\u00fclich GmbH, 52428 J\u00fclich, Germany"},{"name":"Centre for High-Performance Scientific Computing in Terrestrial Systems (TerrSys), Forschungszentrum J\u00fclich GmbH, 52428 J\u00fclich, Germany"}]},{"given":"Johan A.","family":"Huisman","sequence":"additional","affiliation":[{"name":"Institute of Bio- and Geoscience, Agrosphere (IBG-3), Forschungszentrum J\u00fclich GmbH, 52428 J\u00fclich, Germany"},{"name":"Centre for High-Performance Scientific Computing in Terrestrial Systems (TerrSys), Forschungszentrum J\u00fclich GmbH, 52428 J\u00fclich, Germany"}]},{"given":"Achim","family":"Mester","sequence":"additional","affiliation":[{"name":"Central Institute for Engineering, Elektronics and Analytics, Electronic Systems (ZEA-2), Forschungszentrum J\u00fclich GmbH, 52428 J\u00fclich, Germany"}]},{"given":"Daniel","family":"Altdorff","sequence":"additional","affiliation":[{"name":"Institute of Bio- and Geoscience, Agrosphere (IBG-3), Forschungszentrum J\u00fclich GmbH, 52428 J\u00fclich, Germany"},{"name":"Boreal Ecosystem Research Initiative, Memorial University, Corner Brook A2H 5G4, NL, Canada"}]},{"given":"Anthony L.","family":"Endres","sequence":"additional","affiliation":[{"name":"Earth and Environmental Science, University of Waterloo, Waterloo N2L 3G1, ON, Canada"}]},{"given":"Egon","family":"Zimmermann","sequence":"additional","affiliation":[{"name":"Central Institute for Engineering, Elektronics and Analytics, Electronic Systems (ZEA-2), Forschungszentrum J\u00fclich GmbH, 52428 J\u00fclich, Germany"}]},{"given":"Sarah","family":"Garr\u00e9","sequence":"additional","affiliation":[{"name":"Gembloux Agro-Bio Tech, Li\u00e8ge University, 5030 Gembloux, Belgium"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8051-8517","authenticated-orcid":false,"given":"Harry","family":"Vereecken","sequence":"additional","affiliation":[{"name":"Institute of Bio- and Geoscience, Agrosphere (IBG-3), Forschungszentrum J\u00fclich GmbH, 52428 J\u00fclich, Germany"},{"name":"Centre for High-Performance Scientific Computing in Terrestrial Systems (TerrSys), Forschungszentrum J\u00fclich GmbH, 52428 J\u00fclich, Germany"}]}],"member":"1968","published-online":{"date-parts":[[2019,11,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"W00D18","DOI":"10.1029\/2008WR007043","article-title":"Geophysical imaging of watershed subsurface patterns and prediction of soil texture and water holding capacity","volume":"44","author":"Abdu","year":"2008","journal-title":"Water Resour. 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