An analytical four-layer horizontal electric current dipole model for analysing underwater electric potential in shallow seawater

Abstract

The paper presents a new analytical four-layer (air–water–bottom–non-conductive layer) horizontal electric dipole model which allows an accurate approximation of ship's Underwater Electric Potential (UEP) from a sufficient depth in shallow coastal marine waters. The numerical methods, usually Finite Element Method (FEM) or Boundary Elements Method (BEM), are typically used to estimate the electric field and the distribution of static electric components of UEP around the ship. These methods enable analyses with high accuracy but, compared to other point-electrode methods and the proposed analytical model, they are relatively complex and need high computational time. The developed analytical model proposed in this paper allows real-time calculations without significant loss of accuracy of the UEP estimations. In the model, the problem of boundary values at the borders of individual layers is solved using the reflection/image method and applying the idea of continuity of electric potential at a given boundary between two adjacent layers. Its accuracy is verified based on the synthetic data provided by specialised software packages making use of FEM and BEM numerical methods. A dimensionless quantitative analysis of the relationships between basic parameters of the proposed four-layer analytical model and their impact on the accuracy of representation of individual electric field strength components is also delivered. The relationships between water and bottom conductivity and between water depth and bottom thickness are investigated and described. The obtained results show that the developed model allows detailed and reliable analysis of the electric field, especially in shallow coastal waters.

Modelling of an Efficient Electromagnetic Method for Underwater Wireless Communication

“…Over the past several decades, the increasing demand for underwater resources, underwater communication links, and assisting robots has received wide interest. [1]. For underwater operations, when a single robot is performing a task, the stationary and very far regulator center should observe the state of the robot and carry out some required targets on the receiving end through the subaquatic communicating link [2].…”

Capabilities to use passive measurement systems to detect objects moving in a water region

“…These disturbances can be referred to the upper (air space) and lower (underwater) hemisphere. In the upper hemisphere the motion of the object generates disturbances of the thermal field (J. J. Holmes 2022; ) while in the lower hemisphere disturbances of the acoustic, hydrodynamic, magnetic, electric and seismic fields are generated (Wołoszyn et al 2022;Tarnawski et al 2021;Buszman 2020). Detection of the floating objects and determination of movement parameters is realized mainly by active systems.…”

Incoherent Shallow-Water Seabed Logging Using Numerical-Model-Based Optimization for the Prediction of Unperturbed UEP Signatures

“…In the field of underwater communications, for example, methods for locating objects near the seabed have been researched for many years [1,2]. In recent years, an attempt to compute shallow water signatures from stationary signatures was published by a group in 2022, which is based on an analytical computational model [3]. For numerical models, a PSO optimization method was presented in 2020 to perform inversions of UEP signatures associated with the representation of vessels emitting only DC signatures [4].…”