圓錐型場源瞬變電磁法測量數據反演

作者：楊海燕,李鋒平,Chen Shen-En,岳建華,郭福生,陳曉,Zhang Hua

摘要：Multiturn coils is an effective transmitter for transient electromagnetic method(TEM)used in narrow space and complex terrain at presently.However,its high mutual inductance coupling and long turn-off time affect the quality of later data processing and interpretation.Compared with multiturn coils,the new conical source has low mutual inductance and short turn-off time.Based on the superposition principle,we use Hankel transform and numerical fi ltering method for forward modelling of the conical source fi eld in the layered-media and explore TEM characteristics excited by this source.We apply improved damped least square inversion to integrated transient electromagnetic(TEM)data.We first invert the induced voltage into similar resistivity and apparent depth,and then use the inverted results as input parameters in the initial model and transform the apparent resistivity data into the frequency domain.Then,damped least square inversion is performed in the frequency domain using the initial model.Subsequently,we use automated model building to search for the extremes and infl ection points in the resistivity–depth data that are treated as critical layer parameters.The inversion of theoretical and observed data suggests that the method modifi es the resistivity and depth and yields a model of the underground layers.

發文機構：State Key Laboratory Breeding Base of Nuclear Resources and Environment School of Resource and Earth Science Department of Civil and Environmental Engineering

關鍵詞：Transientelectromagneticmethodcone-shapedsourcesmoking-ringINVERSIONDAMPEDleastsquareINVERSIONAPPARENTRESISTIVITY

分類號： O441[理學—電磁學][理學—物理]