A lightning flash, cloud or cloud-to-ground, can be modeled by a time-varying dipole, whose orientation may differ significantly from vertical, especially for cloud flashes. A direction finder measuring the vertical electric field and the horizontal components of the magnetic field over an infinitely conducting ground can estimate the location of the dipole with an accuracy that depends on the dipole orientation. A vertical dipole gives the best accuracy and a horizontal one the worst. With more than one direction finder, at different sites, the uncertainty for a nonvertical dipole can be removed. The method is based on the use of a pseudodirection angle, which for a vertical dipole coincides with the actual direction, and various time derivatives of the received signal. ¿ American Geophysical Union 1996