A Novel Low-Frequency Lateral Wave Approximation Formula of Submerged Magnetic Dipoles Near Sea Surface

Lateral waves (LW) excited by submerged magnetic dipoles near the sea surface are important for underwater magnetic induction communication and sensing. Existing approximation formulas are only suitable for far-field regions and accurate only when the source and field points are placed at the same depth. In this letter, a novel approximation formula of the LW excited by submerged magnetic dipoles is proposed by adopting the asymptotic expansion method. Numerical results show that the proposed formula is applicable to any frequency up to 100 MHz for both near and far fields in an underwater environment of dynamic conductivity. Moreover, it is accurate when the source and field points are placed at both the same depth and different depths. The proposed formula can serve as a valuable tool to accurately design and analyze underwater magnetic induction communication.