This research study investigated the composite magnetic fields of underwater vehicles in the presence of ocean waves under varying conductivity, analyzed their spatiotemporal characteristics, attenuation laws, and influence mechanism. We integrated the modeling of three types of magnetic fields to obtain a composite magnetic field: the magnetic anomaly field generated by a ferromagnetic vehicle was simulated with a hybrid ellipsoid–dipole model, the wake magnetic field generated by its motion, and the ocean wave magnetic field generated by wind-driven waves were derived from the velocity fields. Simulation results show that the magnetic anomaly and wake magnetic fields are mainly influenced by vehicle speed, course, and diving depth, while the ocean wave magnetic field is affected by wind speed and direction. The composite magnetic field’s intensity increases with vehicle and wind speed but decreases with the increase in diving depth. This study offers a comprehensive analysis of the composite magnetic fields of underwater vehicles in the presence of ocean waves, emphasizing the significant impact of vehicle motion and marine environmental parameters. These insights are essential to gaining a deeper understanding of the magnetic fields generated by underwater vehicles as they navigate ocean waves.

High-precision magnetic anomaly field modeling is crucial for the development of magnetic detection and stealth technologies of submerged vessels. This paper aims to reveal how depth and speed influence the magnetic anomaly field of submerged vessels, thus providing a theoretical foundation for magnetic stealth and detection technologies. A single-shell vessel model without appendages was developed to simplify magnetic characteristic analysis. The finite element method, based on Gauss's law for magnetism and Maxwell-Ampere's law, was employed to compute the spatial characteristics of the magnetic anomaly field. Moreover, the stationary solution and parametric sweep analysis were integrated to simulate the temporal characteristics of the magnetic anomaly field as the vessel sailed at different depths and speeds. The results indicate that the magnetic anomaly field intensity peaks directly above the vessel and diminishes with increasing detection distance. The maximum absolute values of the magnetic anomaly vector field are inversely proportional to depth, with the $\boldsymbol{x}$ -component being dominant, followed by the $z$ - and $\boldsymbol{y}$ -components. Additionally, the depth most impacts the $z$ -component and least the $\boldsymbol{x}$ -component. As the vessel's speed increases, the traversal time shortens and waveform width narrows, but the intensity remains largely unaffected. In conclusion, this research offers essential theoretical support for the magnetic detection and stealth of submerged vessels. Future research should take into account more complex vessel models and real-experiment data.

Accurate modeling of submarine magnetic anomaly characteristics is a fundamental component in evaluating magnetic stealth capabilities. Previous studies have primarily focused on analyzing the spatial magnetic anomaly induced by stationary submarines, with insufficient attention given to the comprehensive impact mechanisms of varying speed, course, and depth in moving submarines. This paper provides a detailed analysis of the spatiotemporal characteristics of submarine magnetic anomaly under typical motion scenarios. Initially, a foundational research submarine model was established using the finite element method (FEM), followed by an examination of the spatiotemporal characteristics of magnetic anomaly during both routine cruise and evasive maneuver scenarios. The simulation results reveal several key findings: 1) During routine cruising, the magnetic anomaly induced by the submarine is not significantly affected by its speed, to reduce the risk of detection by aircraft with magnetic anomaly detection (MAD) sensors, submarines should maintain a relatively high speed to quickly exit hazardous waters. 2) During evasive maneuvering, the magnetic anomaly is slightly stronger when turning left than turning right at a fixed depth, and it is lower at larger elevator angles during emergency diving. Therefore, to reduce the risk of detection by aircraft, submarines should opt for a right rudder angle or a larger elevator angle. 3) When the angle remains the same during evasive maneuvering, submarine exhibits superior magnetic stealth capabilities in emergency diving compared to depth-fixed turning. 4) Combining a specific rightward rudder angle with an elevator angle is the most effective evasive maneuver for submarines. This approach ensures stability and safety by preventing excessive bow tilt and potential instability. The research methodology proposed in this paper has potential value to enhance the development of submarine magnetic stealth technologies.

This study aims to enhance the detection performance of Unmanned Aerial Vehicles (UAVs) for underwater targets by optimizing a detection probability model that incorporates precise modeling of the target's magnetic anomaly field. The Finite Element Method (FEM) is utilized to set up a detailed model of the target’s magnetic anomaly field, which is then integrated into a detection probability model. Through detailed simulations, the influence of various UAV flight parameters on detection probability is evaluated. The results indicate that detection probability is notably improved by lowering flight altitude or by adjusting flight direction. This research significantly contributes to the field by proposing an advanced method for UAV detection probability analysis grounded in an enhanced magnetic anomaly field model of underwater target.