Localization Model of Alternating Magnetic Dipoles in Seawater

Unmanned Underwater Vehicles (UUVs), as core platforms for deep-sea exploration and operations, require precise positioning capabilities. Traditional acoustic positioning systems often suffer from insufficient accuracy in near-field UUV positioning due to sea surface reflections and obstacle interference, while existing electromagnetic positioning methods overlook the attenuation effects of magnetic dipole signal propagation in seawater, resulting in low precision. To address these challenges, this paper proposes a novel magnetic dipole localization model in seawater. By analyzing the propagation characteristics of magnetic dipole signals in conductive media, we overcome the limitations of both traditional acoustic systems and current electromagnetic methods. Simulations were conducted with 12 sensors receiving radiation signals from moving magnetic dipoles in seawater. Localization inversions were performed using the Levenberg-Marquardt algorithm under two conditions: a seawater model that accounts for electromagnetic wave attenuation and an air model that neglects it. The results demonstrate that the seawater model outperforms the air model in terms of localization accuracy.