Efficient Method for Solving Underwater Electromagnetic Fields Generated by Radiation Sources in Seawater

Underwater electromagnetic (EM) waves are one of the important carriers for information exchange in seawater. It is necessary to study the propagation characteristics to ensure their application in seawater. However, the existence of the underwater radiation source makes the amplitude coefficients in the seawater layer vary greatly, which increases the difficulty of solving the underwater EM field. There are no good targeted solutions carried out in existing studies. In this letter, a new efficient method is proposed to solve the underwater EM field generated by radiation sources in seawater. This method divides the EM field in seawater into the secondary field and the background field. The effects of singularities produced by radiation sources are overcome, and the difference between the amplitude coefficients in the solution equation is reduced by discarding the use of amplitude coefficients from the radiation source. Except for the background field, the method does not require more additional calculations and space compared to traditional methods. Underwater EM fields can be obtained with lower computing resources and shorter computing time. In addition, experiments and numerical simulations were conducted to verify the accuracy, efficiency, and universality of this method. The results show that this method is superior to the traditional method in both efficiency and accuracy.