 Unlike them it is used for geophysical research in addition to military communications.The Indian Navy has an operational ELF communication facility at the INS Kattabomman naval base, in Tamil Nadu, to communicate with its Arihant class and Akula class submarines.The total power radiated by a ground dipole is
where is the frequency, is the RMS current in the loop, is the length of the transmission line, is the speed of light, is the height above ground of the ionosphere D layer, and is the ground conductivity.