Details of the Abstract
| Title of paper | Airborne Natural Source Electromagnetics for an Arbitrary Base Station |
| List of authors | Cowan, D. C., Heagy, L. J., and Oldenburg, D. W. |
| Affiliation(s) | University of British Columbia Geophysical Inversion Facility |
| Summary | Airborne magnetotelluric (AirMT) systems generate transfer function data from magnetic fields measured in the air, and either electric or magnetic fields measured at a base station. The transfer function data collected during an AirMT survey is system dependent. Therefore, data collected by various AirMT systems may not recover the same conductivity model when inverted using the same set of inversion parameters. In this abstract, we describe fundamental similarities and differences between AirMT systems that measure magnetic fields versus electric fields at the base station. Synthetic modeling is used to show that AirMT anomalies are fundamentally controlled by the anomalous magnetic fields within the survey region. AirMT data acquired using a magnetic field base station are not directly sensitive to the conductivity at the base station, whereas AirMT data acquired using an electric field base station are scaled by the inverse square root of the conductivity at the base station. Using an unconstrained inversion approach and assuming a distant base station, we determined that when a-priori knowledge of the host conductivity within the survey region is available, AirMT inversion effectively recovers conductive and resistive structures within the survey region. This is true regardless of the fields that are measured at the base station. |
| Session Keyword | 2.0 EM theory, modelling and Inversion |
| File upload |
2.0_airborne_natural_source_e_cowan.pdf
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