Abstract:
Airborne magnetotelluric method is an airborne frequency-domain electromagnetic method that measures the natural electromagnetic fields. It has the advantages of great detection depth, high measurement efficiency, minimal terrain influence, and being environmentally friendly. This paper briefly introduced the development history and measurement principles of airborne magnetotelluric method. Then introduced the basic concept of admittance tensor and the working methods of airborne magnetotelluric measurement using admittance tensor. Finally, this method was applied to engineering surveys under complex terrain conditions. By analyzing the characteristics of inversion resistivity and magnetic susceptibility, effective detection of rock masses and fracture structures was achieved. Application example showed that the airborne magnetotelluric method based on the admittance tensor is sensitive to geoelectric boundary and can be used for detecting near-surface and deep structures in complex environmental areas.