Electromagnetic tomography: dyadic Green's function method

This study aims at formulating a dyadic Green" s function method for directly solving the forward and inverse problems of the electromagnetic tomography (EMT) with parallel field sensor. First, an integral equation of the electromagnetic problem for the EMT sensor is presented in terms of an equivalent source, which takes the dyadic Green’s function G(r,r’) as its kernel. Next, starting from a single conducting cylinder filled with homogeneous medium, a convenient way of finding the electric dyadic Green’ s function of the first kind Get( r, r) is described based on the method of Gm. Then, an eigenfunction expansion of the Gel( r, r) into vector wave functions M and N is obtained by means of a contour integration. Finally, an expression of the G( r, r’), the dyadic Green’s function for the EMT sensor with cylindrically layered structure, is deduced from Gel(r,r) by adding reflected wave terms to it.