Subsea cable tracking in an uncertain environment using particle filters

Localization of subsea cables is a demanding and challenging task. Among the few methods reported in the literature, magnetic field detection is the most promising one, as the cable does not require to be seen visually. Magnetic noise and a quick attenuation of the magnetic field propagating in sea water often make available methods unreliable. The authors propose a novel method of using particle filters for estimating the position of a subsea cable in a highly uncertain environment. The method was tested on data collected from a buried cable in the Baltic Sea, Denmark and shown to have a close approximation to the true location of the subsea cable. The method can be used to localize a subsea cable in an offshore noisy and uncertain environment and provides an inexpensive alternative to the use of a diver or a remotely operated platform

Subsea cable tracking by an unmanned surface vehicle

Subsea cable localisation is a demanding task that requires a lot of time, effort and expense. In the present paper the authors propose a methodology that is automated and inexpensive, based on magnetic detection from a small unmanned surface vehicle (USV) and the use of a batch particle filter (BPF) algorithm. A dynamic path planning algorithm for the USV is also developed so that adequate samples of the magnetic field readings can be gathered for processing by the BPF. All of these elements work together online as the cable is tracked, which was demonstrated in a simulated mission

Developments in subsea power and telecommunication cables detection: Part 2 - Electromagnetic detection

The detection and maintenance of power and telecommunication subsea cables are often difficult and dangerous. Globally, engineers have approached such tasks using different methods. Although the subject is of great importance, there is no single universally accepted method or even agreement about existing methods. This review focuses on electromagnetic detection as a widely used technique for detection of buried cables. The paper reviews practical methods used in electromagnetic detection of subsea cables and ferromagnetic objects. It begins describing the use of simple searching coils carried by a diver and concludes with techniques that implement magnetometers on autonomous survey platforms. The methods used in electromagnetic subsea cable detection are often based on simple and established technologies. Despite this, detection of general ferromagnetic objects in the subsea environment is an active area of research. This review also describes developments in underwater unexploded ordnance detection, which can be technologically transferred to the detection of power and telecommunication cables

Point localisation of a subsea cable using particle filters

Point localisation of subsea cables are necessary as a starting point in the search of a particular section or whole length of a cable and become a demanding and challenging task in an uncertain environment such as sea. The authors propose a novel method of using particle filters for estimating the position of a subsea cable in a highly uncertain environment. The method was tested on data collected from a buried cable in the Baltic sea, Denmark and shown to have close approximation to the true location of the subsea cable. The method can be used to localise a subsea cable in an off-shore noisy and uncertain environment and provides an inexpensive alternative to the use of a diver or a remotely operated platform

Developments in subsea power and telecommunication cables detection: Part 1 - Visual and hydroacoustic tracking

Subsea power and telecommunication transmission lines play an important role in today's world. They not only provide a link from shore to shore, but also connect an increasing number of offshore wind farms, wave power plants and other sea installations. Subsea cables have to be periodically maintained and checked for movement in terms of their position and burial depth. This task is difficult because of the dynamic environment of the sea floor, which can cause changes in position, depth, visibility and access to the utilities. In this review, developments in visual and hydroacoustic tracking are discussed, as are theoretical and practical concerns. This review also describes methods and tools for detection of the transmission lines laid on a seabed. Finally, it highlights the need to construct a simple reliable system to estimate the position and burial depth of subsea transmission lines

Range Extension for Electromagnetic Detection of Subsea Power and Telecommunication Cables

Subsea cables protection afforded by burying a cable [beneath the sea bed] also means that the available methods for their survey are drastically reduced. From the existing methods only electromagnetics (EM) detection can penetrate the sea bed and provide an effective means for cable localisation. However, EM waves attenuate faster in conductive media such as sea water. EM localisation is considered a short range detection mechanism requiring the use of autonomous or remotely operated underwater platforms. In this paper, the authors investigate the range of EM detection and test detection distances exceeding one hundred metres. The EM signal was detected at distances around 140 m in sea water during the trials conducted in a ‘real’ environment at Hooe Lake in Plymouth