AN ANALYSIS OF A STAKED DIPOLE PROBE ON A LOSSY EARTH PLANE USING THEFINITE-DIFFERENCE TIME-DOMAIN METHOD

Using the finite difference time-domain (FDTD) method, an electrically short, staked, grounded horizontal probe is shown to hale an open cir cuit voltage directly related to the horizontal electric field at the earth's surface providing the surface coupling is subtracted from the output, This result is valid not only for an infinitely deep earth pla ne but also for one which is horizontally layered. The effective lengt h of a staked probe is found to be dependent on the conductivity of th e upper layer of the earth, its depth, the length of the stakes, and a lso the frequency of measurement, The effect is significant at very lo w frequency (VLF) for ice, permafrost and dry sand-covered regions.