Effect of seawater on radiation field of electric dipole

The corrosion and corrosion resistance current of the submarine will produce extremely low frequency electric field after modulated by the propeller rotation in the seawater. It becomes one of the most important characteristics of the signal source. We derive the expression for the electric and magnetic fields of the electric dipole in the seawater using the electric Hertz vector, also give the expressions for the standard field. Measurements and numerical simulations show that the standard field amplitude of the submarine in the shaft frequency is in a great location. And the shaft - rate electric field can be received in a long distance. Therefore, submarine detection using the shaft - rate electric field can be probably best carried out.