Interpretation of transient electromagnetic field data using joint time-frequency analysis
瞬变电磁场资料的联合时-频分析解释

Using the joint time-frequency (TF) analysis method, we interpret transient electromagnetic (TEM) data so as to fully employ information contained in TEM signals. We chose joint TF distribution (or representation) of Wigner-Will distribution and Gabor expansion to transform the one-dimensional time-domain signal to two-dimensional TF plane, which not only distinguishes responses of the different geo-electric sections from each other successfully, but also provides clear physical meaning between exhibited signal feature and electrical structure of the stratum. This describes the transient eddy field exciting and underground attenuating process in time and frequency respects. The fitting difference is reduced and the precise of quantitative interpretation is improved by means of joint TF inversion with time and frequency window data.