Identification of a transient dipole source over a perfectly conducting ground by measuring electromagnetic fields at several ground points is considered. It is shown that the full information concerning the dipole source (including the location, the orientation, and the transient moment of the dipole) can be determined uniquely by measuring the electromagnetic fields at two ground points if the dipole orientation does not lie on the plane formed by the dipole and the two measurement points. Explicit identification formulas are given to reconstruct all the parameters which describe the transient dipole source. Under any circumstances all the parameters can be determined by measurements at any three ground points which are not along a line. The reconstruction algorithm is tested with clean and noisy data. ¿ 2000 American Geophysical Union