DESMEX: A novel system development for semi-airborne electromagnetic exploration
(2020) In Geophysics 85(6). p.253-267- Abstract
- There is a clear demand to increase detection depths in the context of raw material exploration programs. Semi-airborne electromagnetic (semi-AEM) methods can address these demands by combining the advantages of powerful transmitters deployed on the ground with efficient helicopter-borne mapping of the magnetic field response in the air.The penetration depth can exceed those of classical airborne EM systems,since low frequencies and large transmitter-receiver offsets can be realized in practice. A novel system has been developed that combines high-moment horizontal electric bipole transmitters on the ground with low-noise three-axis induction coilmagnetometers, a three-axis fluxgate magnetometer and a laser gyroinertial measurement unit... (More)
- There is a clear demand to increase detection depths in the context of raw material exploration programs. Semi-airborne electromagnetic (semi-AEM) methods can address these demands by combining the advantages of powerful transmitters deployed on the ground with efficient helicopter-borne mapping of the magnetic field response in the air.The penetration depth can exceed those of classical airborne EM systems,since low frequencies and large transmitter-receiver offsets can be realized in practice. A novel system has been developed that combines high-moment horizontal electric bipole transmitters on the ground with low-noise three-axis induction coilmagnetometers, a three-axis fluxgate magnetometer and a laser gyroinertial measurement unit integrated within a helicopter-towed airborne platform. The attitude data are used to correct the time series for motional noise and subsequently to rotate into an Earth-fixed reference frame. In a second processing step, and as opposed to existing semi-airborne systems, we transform the data into the frequency domain and estimate the complex-valued transfer functions between the received magnetic field components and the synchronously recorded injection current by regression analysis. This approach is similar to the procedure employed in controlled-source EM. For typical source bipole moments of 20-40 kAm and for rectangular current waveforms with a fundamental frequency of about 10 Hz, we can estimate reliable three-component transfer functions in the frequency range from 10-5000 Hz over a measurement area of 4 x 5 km2 for a single source installation. The system has the potential to be used for focused exploration of deep targets. (Less)
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- author
- organization
- publishing date
- 2020
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- electromagnetics, processing, airborne survey
- in
- Geophysics
- volume
- 85
- issue
- 6
- pages
- 15 pages
- publisher
- Soc Exploration Geophysicists
- external identifiers
-
- scopus:85102111919
- ISSN
- 0016-8033
- DOI
- 10.1190/geo2019-0336.1
- language
- English
- LU publication?
- yes
- id
- 26e721a2-7ba8-49ba-a92f-84b7dfedd987
- alternative location
- https://library.seg.org/doi/epdfplus/10.1190/geo2019-0336.1
- date added to LUP
- 2020-11-18 09:16:19
- date last changed
- 2022-04-26 21:54:37
@article{26e721a2-7ba8-49ba-a92f-84b7dfedd987,
abstract = {{There is a clear demand to increase detection depths in the context of raw material exploration programs. Semi-airborne electromagnetic (semi-AEM) methods can address these demands by combining the advantages of powerful transmitters deployed on the ground with efficient helicopter-borne mapping of the magnetic field response in the air.The penetration depth can exceed those of classical airborne EM systems,since low frequencies and large transmitter-receiver offsets can be realized in practice. A novel system has been developed that combines high-moment horizontal electric bipole transmitters on the ground with low-noise three-axis induction coilmagnetometers, a three-axis fluxgate magnetometer and a laser gyroinertial measurement unit integrated within a helicopter-towed airborne platform. The attitude data are used to correct the time series for motional noise and subsequently to rotate into an Earth-fixed reference frame. In a second processing step, and as opposed to existing semi-airborne systems, we transform the data into the frequency domain and estimate the complex-valued transfer functions between the received magnetic field components and the synchronously recorded injection current by regression analysis. This approach is similar to the procedure employed in controlled-source EM. For typical source bipole moments of 20-40 kAm and for rectangular current waveforms with a fundamental frequency of about 10 Hz, we can estimate reliable three-component transfer functions in the frequency range from 10-5000 Hz over a measurement area of 4 x 5 km2 for a single source installation. The system has the potential to be used for focused exploration of deep targets.}},
author = {{Becken, Michael and Nittinger, Christian G. and Smirnova, Maria and Steuer, Annika and Martin, Tina and Petersen, Hauke and Meyer, Uwe and Mörbe, Wiebke and Yogeshwar, Pritam and Tezkan, Bülent and Matzander, Ullrich and Friedrichs, B and Rochlitz, Raphael and Günther, Thomas and Schiffler, Markus and Stolz, Ronny}},
issn = {{0016-8033}},
keywords = {{electromagnetics; processing; airborne survey}},
language = {{eng}},
number = {{6}},
pages = {{253--267}},
publisher = {{Soc Exploration Geophysicists}},
series = {{Geophysics}},
title = {{DESMEX: A novel system development for semi-airborne electromagnetic exploration}},
url = {{http://dx.doi.org/10.1190/geo2019-0336.1}},
doi = {{10.1190/geo2019-0336.1}},
volume = {{85}},
year = {{2020}},
}