Direct Time-domain Solution of Transient Electromagnetic Field in Homogeneous Conductive Full Space

Dipole hypothesis is the basis of the definition of all-zone and full-time apparent resistivity in classic transient electromagnetic theory. However, the dipole hypothesis is not a good approximation in near-source zone because the finite length of the dipole. With the fast development of near-source TEM, it is necessary to turn the traditional dipole into point charge. TEM all-zone field analytical solution has been derived by introducing time-domain Green function. Direct time-domain exact potential function and electromagnetic solutions of damped wave equations in homogeneous conductive full space have been derived. The direct time-domain solution is more accurate than the traditional quasi-static solution of dipole. This research lays a solid theoretical foundation for detection in TEM near-source zone.