A hexacopter unmanned aircraft system instrumented with a caesium vapour magnetometer recorded total magnetic intensity over a 5.0 km2 prospective gold area in the Abitibi Subprovince of the Canadian Precambrian Shield. The survey also included a N–S repeatability line which showed that the unmanned aircraft system was very stable in flight with average standard deviations from nominal altitude and easting being 1.8 m and 0.7 m, respectively. The total magnetic intensity map revealed the structural framework of the banded iron formations present in the survey area and showed that the gold ore zones are not directly associated with magnetic highs but rather with steeply dipping faults. The total magnetic intensity data was inverted in 3-D using unconstrained and constrained approaches with 12.5 m (northing) × 12.5 m (easting) × 5 m (depth) cells and a maximum of 20 iterations. The processed (after diurnal corrections, heading correction, and tie-line levelling) total magnetic intensity data was input directly in the unconstrained inversion algorithm. Initial model building for the constrained inversion was a much more laborious process involving the inclusion of 15 synthetic structures based on borehole magnetic susceptibility measurements and knowledge of the local geology. The results of both inversion approaches were very similar. They revealed the presence of near-vertical thin sheets, individually resolvable down to approximately 400 m. In this particular case, the straightforward unconstrained inversion yielded a realistic and detailed model of the subsurface in approximately 1 h of runtime. Unmanned aircraft system total magnetic intensity data could therefore be processed and inverted almost immediately after acquisition and have an impact on decisions made in the field while a survey is still in progress.
This is a preview of subscription content, access via your institution.
Buy single article
Instant access to the full article PDF.
Tax calculation will be finalised during checkout.
Subscribe to journal
Immediate online access to all issues from 2019. Subscription will auto renew annually.
Tax calculation will be finalised during checkout.
Carrier, A., Nadeau-Benoit, V., & Faure, S. (2019). NI 43-101 Technical report and initial mineral resource estimate for the Nelligan Project, Quebec, Canada. Accessed 08–01–2020, https://vanstarmining.com/wp-content/uploads/2019/12/IAMGOLD_VANSTAR_43-101_FINAL.pdf.
Cherkasov, S., Sterligov, B., & Zolotaya, L. (2016). On the use of unmanned aerial vehicles for high-precision measurements of the Earth’s magnetic field. Moscow University Geological Bulletin., 71(4), 296–299. https://doi.org/10.3103/S0145875216040037.
Chown, E. H., Daigneault, R., & Mueller, W. (1991). Part 1: geological Setting of the eastern Extremity of the Abitibi Belt. In: 8th IAGOD Symposium, Ottawa, Ontario; CA; August 12–18, 1990. https://doi.org/10.4095/132277
Clark, D. A. (1997). Magnetic petrophysics and magnetic petrology: aids to geological interpretation of magnetic surveys. AGSO Journal of Australian Geology and Geophysics, 17(2), 83–103.
Coyle, M., Dumont, R., Keating, P., Kiss, F., & Miles, W. (2014). Aeromagnetic surveys: Design, quality assurance, and data dissemination. Geological Survey of Canada Open File, 7660, 48. https://doi.org/10.4095/295088 (Pei 2017).
Cunningham, M., Samson, C., Wood, A., & Cook, I. (2018). Aeromagnetic surveying with a rotary-wing unmanned aircraft system: a case study from a zinc deposit in Nash Creek, New Brunswick Canada. Pure and Applied Geophysics., 175, 3145–3158.
Daigneault, R., Mueller, W. U., & Chown, E. H. (2004). Abitibi greenstone belt plate tectonics: the diachronous history of arc development, accretion and collision. In P. G. Eriksson, W. Altermann, D. R. Nelson, W. U. Mueller, & O. Catuneanu (Eds.), The Precambrian earth: tempos and events, series: developments in Precambrian geology (Vol. 12, pp. 88–103). Amsterdam: Elsevier.
Dentith, M., & Mudge, S. T. (2014). Geophysics for the mineral exploration geoscientist. Cambridge: University Press.
Huq, M., Forrester, R., & Ahmadi, M. (2015). Magnetic characterization of actuators for an unmanned aerial vehicle. IEEE/ASME Transactions on Mechatronics., 20(4), 1986–1991.
Lee, M., & Morris, W. (2013). Quality assurance of aeromagnetic data using lineament analysis. Exploration Geophysics, 44, 104–113.
Malehmir, A., Dynesius, L., Paulusson, K., Paulusson, A., Johansson, H., Bastani, M., et al. (2017). The potential of rotary-wing UAV-based magnetic surveys for mineral exploration: A case study from central Sweden. Leading Edge, 36(7), 552–557. https://doi.org/10.1190/tle36070552.1.
Parshin, A., Morozov, V., Blinov, A., Kosterev, A., & Budyak, A. (2018). Low-altitude geophysical magnetic prospecting based on multirotor UAV as a promising replacement for traditional ground survey. Geo-spatial Information Science, 21(1), 67–74. https://doi.org/10.1080/10095020.2017.1420508.
Parvar, K., Braun, A., Layton-Matthews, D., & Burns, M. (2018). UAV magnetometry for chromite exploration in the Samail ophiolite sequence Oman. Journal of Unmanned Vehicle Systems, 6(1), 57–69. https://doi.org/10.1139/juvs-2017-0015.
Pei, Y., Liu, B., Hua, Q., Liu, C., & Ji, Y. (2017). An aeromagnetic survey system based on an unmanned autonomous helicopter: Development, experiment, and analysis. International Journal of Remote Sensing, 38(8–10), 3068–3083. https://doi.org/10.1080/01431161.2016.1274448.
SIGEOM. (2020). Système d'information géominière du Québe. Accessed: 15 July 2020. http://sigeom.mines.gouv.qc.ca/
Sterligov, B., & Cherkasov, S. (2016). Reducing magnetic noise of an unmanned aerial vehicle for high-quality magnetic surveys. International Journal of Geophysics, 2016, 1–7. https://doi.org/10.1155/2016/4098275.
Sterligov, B., Cherkasov, S., Kapshtan, D., & Kurmaeva, V. (2018). An experimental aeromagnetic survey using a rubidium vapor magnetometer attached to the rotary-wings unmanned aerial vehicle. First Break, 36(1), 39–45.
Stoll, J. (2013). Unmanned aircraft systems for rapid near surface geophysical measurements. The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. https://doi.org/10.5194/isprsarchives-XL-1-W2-391-2013.
Taner, M. F., & Chemam, M. (2015). Algoma-type banded iron formation (BIF), Abitibi Greenstone belt, Quebec, Canada. Ore Geology Reviews, 70, 31–46.
Tuck, L., Samson, C., Laliberté, J., Wells, M., & Bélanger, F. (2018). Magnetic interference testing method for an electric fixed-wing unmanned aircraft system (UAS). Journal of Unmanned Vehicle Systems., 6, 177–194. https://doi.org/10.1139/juvs-2018-0006.
Tuck, L., Samson, C., Polowick, C., & Laliberté, J. (2019). Real-time compensation of magnetic data acquired by a signle-rotor unmanned aircraft system. Geophysical Prospecting., 67, 1637–1651. https://doi.org/10.1111/1365-2478.12800.
Vallée, M., Farquharson, C., Morrison, W., King, J., Byrne, K., Lesage, G., et al. (2019). Comparison of geophysical inversion programs run on aeromagnetic data collected over the Highland Valley Copper district, British Columbia Canada. Exploration Geophysics., 50(3), 310–323.
Walker, S. (2018). Sometimes innovative tools require an FAQ: lessons learned inverting magnetic data. SEG Technical Program Expanded Abstracts. https://doi.org/10.1190/segam2018-2998403.1.
Walter, C., Braun, A., & Fotopoulos, G. (2019a). High-resolution unmanned aerial vehicle aeromagnetic surveys for mineral exploration targets. Geophysical Prospecting., 68, 334–349. https://doi.org/10.1111/1365-2478.12914.
Walter, C., Braun, A., & Fotopoulos, G. (2019b). Spectral analysis of magnetometer swing in high-resolution UAV-borne aeromagnetic surveys. IEEE Stratus. https://doi.org/10.1109/stratus.2019.8713313.
Walter, C., Braun, A., & Fotopoulos, G. (2019c). Impact of three-dimensional attitude variations of an unmanned aerial vehicle magnetometry system on magnetic data quality. Geophysical Prospecting., 67, 465–479. https://doi.org/10.1111/1365-2478.12727.
Wood, A., Cook, I., Doyle, B., Cunningham, M., & Samson, C. (2016). Experimental aeromagnetic survey using an unmanned air system. The Leading Edge, 35, 270–273. https://doi.org/10.1190/tle35030270.1.
The authors thank NSERC (Natural Sciences and Engineering Research Council) for providing the Engage Grant to Dr. Claire Samson and scholarship to Michael Cunningham.
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
About this article
Cite this article
Cunningham, M., Samson, C., Laliberté, J. et al. Inversion of Magnetic Data Acquired with a Rotary-Wing Unmanned Aircraft System for Gold Exploration. Pure Appl. Geophys. 178, 501–516 (2021). https://doi.org/10.1007/s00024-021-02664-8
- Unmanned aircraft systems
- Airborne surveying
- Mineral exploration