Technical progress of processing methods for magnetotelluric sounding data
The magnetotelluric sounding method is widely used in researches on geodynamics,metallogenic sys-tem,deep exploration of mineral resource and clean/oil energy and investigation of geological disaster,due to its advantages of large detection depth,penetrating high resistance layers,portable performance and low cost.How-ever,the performance of this method is weak in natural electromagnetic field signals observation,which is easily interfered by noise.The effective electrical information is obtained by long-term observation and multiple super-position,and the related data processing and analysis methods were used to obtain reliable geo-electrical results.Data processing usually includes time-frequency conversion,denoising,estimation of impedance tensor and tip-per vector,and data analysis includes electrical strike direction and medium dimension analysis.In this paper,the authors summarized the widely used processing methods for magnetotelluric sounding data,based on previous re-search and introduced the forefront research directions and achievements focusing on denoising in data processing and impedance and phase tensor in data analysis.The characteristics and advantages of the existing methods,and the applicability to geomagnetic field observation data under different environments and backgrounds were analyzed to provide theorical information and basic guarantee for effective and efficient application of magnetotelluric sounding.
magnetotelluric soundingdata processingdata analysismethod and technique