The Effect Reach Of Transient Electromagnetic Method In The Exploration Of The Coal Mined-out Area

China’s energy structure determines its dependence on coal resources. With thelarge-scale development of coal resources in the tremendous benefits, but also had ahuge risk, that is, coal gob. Especially water gobs of water inrush disaster threateningthe life safety of underground workers. Transient electromagnetic method due to itsfast, efficient and accurate characteristics of the coal mined area survey has beenwidely applied. In this paper, first of transient electromagnetic method starting fromthe Maxwell equations, obtained horizontally layered large geomagnetic dipole sourceand the central loop electromagnetic response, through the formula forone-dimensional model of goaf forward modeling, transient electromagneticdiscussed on gob gob and water response characteristics, and discussed by the current,the coil turns, loops are common side effects of the magnetic moment changes inresponse to changes in features. Then discuss some o f the effects of transientelectromagnetic factors, and the response by the previous discussion and a discussionof factors affecting study the production of some of the field to determine theparameters and calculated by the formula given general parameters of referencevalues. Then summarizes the precautions when field work, describes the commondata processing software and software used in the inversion algorithms, and dataprocessing specific processes. Finally, an example, using the methods discussed inthis paper to determine the parameters to identify the work area gob distributionshows transient electromagnetic method for detecting coal gob effect is remarkable.