One-dimensional Transient Electromagnetic Method Rectangular Wireframe Forward And Electromagnetic Signals Denoising

The idea of using transient electromagnetic field to delineate layered-earth structure is not new. In fact, the theory of TEM (transient electromagnetic method ) is very well developed mainly because all electromagnetic problems in stratified media in which stratification is horizontal and homogeneous are amenable to elegant mathematical solutions. From 1950's, many papers on TEM have been published continuously.In few of the publications, however, are the solutions for electromagnetic field close to a rectangle loop source of current of finite size presented. The development of such solution is necessary because (1) the transmitter power requirement is much less for sounding near a loop than at a distance (when the loop can be regarded as a dipole ) and (2) it is easier to lay a loop of large size in a square or rectangle than a circle.In this thesis the essential theory of 1-D forward for transient electromagnetic field is systematically explained. The problem of a rectangular loop source of current on multilayered earth has been studied and solved. Good results have been obtained and demonstrated. Moreover, The method to reduce the noise in electromagnetic signal by wavelet multiscale decomposition is also explored.