Silent Localization of Underwater Sensors Using Magnetometers

Jonas Callmer,Fredrik Gustafsson,Martin Skoglund

doi:10.1155/2010/709318

Jonas Callmer, Fredrik Gustafsson + Show 1 more

Open Access

https://doi.org/10.1155/2010/709318

Copy DOI

Abstract

Sensor localization is a central problem for sensor networks. If the sensor positions are uncertain, the target tracking ability of the sensor network is reduced. Sensor localization in underwater environments is traditionally addressed using acoustic range measurements involving known anchor or surface nodes. We explore the usage of triaxial magnetometers and a friendly vessel with known magnetic dipole to silently localize the sensors. The ferromagnetic field created by the dipole is measured by the magnetometers and is used to localize the sensors. The trajectory of the vessel and the sensor positions are estimated simultaneously using an Extended Kalman Filter (EKF). Simulations show that the sensors can be accurately positioned using magnetometers.

Highlights

Today, surveillance of ports and other maritime environments is getting increasingly important for naval and customs services
In this paper we propose a method to silently localize underwater sensors equipped with triaxial magnetometers using a friendly vessel with known static magnetization characteristics. (For methods to estimate the magnetic characteristics, see [11].) Each sensor is further equipped with a pressure sensor and an accelerometer used for depth estimation and sensor orientation estimation, respectively
If global vessel position is available throughout the experiment, from Global Navigation Satellite System (GNSS) or using a radar sensor and a sea chart, it can be used as a measurement of the position of the vessel

Summary

Introduction

Surveillance of ports and other maritime environments is getting increasingly important for naval and customs services. Surface vessels are rather easy to detect and track, unlike submarines and other underwater vessels which pose new threats such as terrorism and smuggling. To detect these vessels, an advanced underwater sensor network is necessary. An advanced underwater sensor network is necessary Such sensors can measure fluctuations in for example, magnetic and electric fields, pressure changes, and acoustics. Sometimes the sensors must be deployed fast, resulting in very uncertain sensor positions. These positions must be estimated in order to enable the network to accurately track an alien vessel

Methods

Results

Conclusion