Application of Adaptive Parallel Fast Marching Method in Automatic Submarine Cable Path Planning

Submarine optical fiber cables are essential carriers of international data transmission, and their laying and maintenance require significant investments. However, the failure of the submarine cable may cause severe socioeconomic damages, costs and disruptions. Therefore, it is important to build a cost-effective and resilient submarine cable network that can withstand potential natural or human-made disasters. This paper first discusses the current research progress on submarine cable path planning and cable network design. Next, it focuses on our approach based on a triangulated manifold is used to model the earth's surface based on real-world geographic data. Then, for submarine cable path planning between two given end-points, the fast marching method (FMM) is used to solve a multi-objective path planning problem that takes into account a variety of design considerations aiming to optimize the survivability and cost of submarine cables. This multi-objective problem is then transformed into a single-objective problem by weighted sum method for solution. Finally, to overcome the difficulties associated with the massive data size that are prevalent in practical scalability and high-precision cable path planning design, two methods named multi-resolution and parallel FMM are proposed. Experimental results show the cable paths obtained by the multi-resolution and parallel FMM have lower cost, shorter length, and higher resolution than the results obtained from the sequential FMM method, which help to achieve scalability and high-quality cable path planning in the future.

Submarine landslides frequently damage communication cables and gas pipelines on the ocean floor, resulting in economic losses and social problems. To study the impact of submarine landslide motion on a pipeline or submarine cable, a rotatory apparatus was developed to simulate the interactions between the submarine landslide and cable. Soil and water can be put in the apparatus and a model cable is fixed in the rotatory part, so the relative motion of the landslide and cable can be measured and evaluated. In addition, shear stress gauges, a pore pressure transducer, and a normal stress sensor were installed at the bottom of the apparatus to monitor the stress change during the model slide motion. In this paper, test results of landslide impact force on the cable model are presented to demonstrate the influences of landslide motion velocity, soil type, and cable diameter on the impact forces.

It is essential to design an appropriate submarine cable route to reduce costs and improve reliability. A methodology that can be used for multi-objective optimization in submarine cable route planning is proposed and numerically studied in this paper. The costs and risks are numerically assessed and mapped to the geographical map. The pheromone and heuristic functions of the ant colony optimization (ACO) algorithm are associated with the geographical map of costs and risks, which enables it to search for a submarine cable route with multi-objective optimization. The results show that the submarine cable route designed by the methodology can effectively avoid high-cost and high-risk regions, which means that the designed submarine cable route is cost-effective and highly reliability.

In the international and regional interconnection of the power grid, submarine cable transmission engineering is a critical component for network construction and optimizing energy allocation. This paper describes the condition of the regional power grid interconnection of submarine cable projects around the world since the 1990's and the development trends of cross ocean power grid connection projects in different countries. It summarizes and analyses the electricity transmission method applied in submarine cable projects. It provides references and insights to the research for electricity transmission method used in the cross ocean interconnecting projects and to the choice of transmission method adopted in the interconnecting projects. It points out advantages and shortcomings of the direct current transmission system applied in submarine cable projects and the strong point that VSC HVDC is used in the submarine cable projects. In the process of achieving grid internationalization, regional power grid interconnection and optimal energy allocation, submarine cable transmission engineering is an important component for network construction. In recent years, with the development of international power transmission technology, together with the trend of economic integration, optimal allocation of energy and reducing the impact on the environment, the cross-sea power transmission, manufacturing technology of the submarine cable and submarine cable engineering technology continues to make progress. The construction of submarine cable is constrained by geographical construction conditions, ocean engineering conditions and construction equipment. The construction involves a wide range of technology with a large investment scale and complex techniques. This construction would be separated into two stages. The preparation stage includes engineering design, submarine cable routing, cable manufacturing and transportation. The construction stage is composed of submarine cable routing orientation, submarine cable laying, on-land equipment installation, test and commissioning and quality control of the work. The main elements of the submarine cable transmission project construction includes regional power grid interconnection across the waters, power supply to oceanic islands and an oil drilling platform and transport marine renewable energy through grid-connected. Impacted from international energy resource optimal utilization, improving national energy safety and reliability from each country and realizing power exchange among different countries, the submarine cable construction can continue to push the international energy structure change, establishing global energy structure for a further development.

Marine remote sensing and hydrographic survey equipment can be used to investigate surface and subsurface geological conditions necessary for the planning and siting of submarine cable projects. Use of remote sensing equipment such as side-scan sonar, magnetometers, sub bottom profilers and precision hydrographic survey transducers allow for real shipboard acquisition and interpretation of subsurface geological data to evaluate the feasibility of planned submarine cable routes. This type of survey also provides the most time efficient and cost effective method of evaluating existing geological conditions over of large areas of seafloor surface when planning and siting submarine cable routes. Remote sensing data equipment can be custom designed and modified in the field to provide optimal high resolution imaging for various seabed and geological conditions. Marine remote sensing surveys give a first-cut at interpreting seabed and subsurface geological conditions to effectively evaluate selected linear routes in the field. This data can also be used to evaluate the potential success of various cable installation methods as well as the potential for encountering surface or subsurface obstructions. High-resolution acoustical survey data, however, must be combined with a geological borings program within selected routing segments to confirm remote sensing data interpretations of subsurface geological conditions. After conducting preliminary desktop cable routing and conditions evaluations, remote sensing field surveys are planned and executed to provide confirmatory information on expected seafloor and subsurface geological conditions.

Summary The increasing necessity to integrate a faster exploration process in the marine geoscience field resulted in the diffusion of 3D geological modelling software among companies operating in offshore market sectors, improving geo-hazard assessment also in offshore windfarm industries and submarine cable routes. In this regard, Next Geosolutions took a step forward with the acquisition of a 3D geomodelling software, Leapfrog Works™ (Seequent ©), with the scope to obtain a 3D integrated model along cable routes, representing geotechnical and geophysical information in a single visualization. The dataset to build the model comprises geotechnical data from Cone Penetration Tests and Vibrocores, and high resolution seismics and sub bottom profiler data, deriving from a cable route survey carried out in the North Sea to develop an HVDC electricity transmission link. The integrated block model is created in several steps through RBF interpolation. Although the software shows some limits in the resolution of the model due to a low sampling rate against the survey corridor length, a good manual control allows to manage the result according to the interpretation of the operator. This ensures that 3D geomodelling software is a valid tool to improve geo-marine exploration and geo-hazard analysis.

The 500kV submarine cable route of Hainan Networking System starts from Nanling Village, Jiaowei Township, Xuwen County, Zhanjiang City, Guangdong Province. It crosses the Qiongzhou Strait to Linshi Village, Qiaotou Town, Chengmai County, Hainan Province. Hainan Networking System 500kV AC Submarine Cable is the first ultra-high voltage, large capacity and long-distance cross-sea networking power cable in China. It is 31 km. In this article, there are three main parts. The first part introduces the status of submarine cable monitoring and the BOTDA test principle. The second part is to design a calibration experiment to calibrate the Brillouin temperature coefficient and the Brillouin strain coefficient for the test fiber of the submarine cable. The third part is to design the spatial distribution rate verification experiment of Brillouin optical time domain reflectometry analyzer to ensure the error of equipment and experiment, so that it can be applied in submarine cable in the future.

Submarine cables are vital for transoceanic communication and offshore energy transmission, making accurate route detection and condition assessment essential. This study applies weak magnetic detection and, unlike traditional DC-based approaches, establishes an AC magnetic field model for submarine cables to analyze their field characteristics and the disturbance caused to shipborne sensors. The influences of navigation angle, ship speed, and detection angle on magnetic field intensity and detection accuracy are investigated. Simulation and experimental results-using a 5 A AC excitation under actual burial depth and typical vessel speeds-show good agreement, confirming the model's validity. The proposed AC-based method can accurately identify submarine cable routes and demonstrates strong application potential for future monitoring, maintenance, and marine engineering.

In complex marine environments, submarine cables are exposed to safety risks such as scour, exposure, or displacement, making accurate route detection critical for ensuring long-term reliable operation and maintenance. This paper proposes a method for submarine cable route detection method based on a magnetic anomaly forward modelling. A forward modeling framework of submarine cable magnetic anomalies is established, and cable-environment interactions are simulated using COMSOL software. The effects of different survey heights and orientation angles on magnetic anomaly responses are analyzed to validate the proposed method. Using these simulations, multiple sets of forward-modeled curves are generated, and the distribution characteristics of magnetic anomalies under various conditions are compared. The results provide a theoretical basis for accurate submarine cable route detection and localization.

In order to investigate and demonstrate the technical feasibility of laying a Submarine power cable in the open ocean, in depths exceeding 6000 feet, over difficult volcanic island seabed conditions, a computer assisted control system for cable vessels was developed. The control system was successfully tested at sea in November 1989, achieving three-meter placement accuracy while laying cable along a pre-selected curved route on the seabed. INTRODUCTION A major challenge to laying a proposed power cable between the islands of Maui and Hawaii in the state of Hawaii is the 1900-meter deep Alenuihaha Channel, known for its difficult currents and waves, with an especially difficult rough bottom terrain, necessitating a very narrow and winding cable path. The United states Department of Energy sponsored the Hawaii Deep water Cable Program (HDWC) with the objective of determining the feasibility of laying and operating a Submarine power cable in these waters. After the channel bottom was surveyed by the HDWC program, the best cable route identified during the surveys was found to narrow in one area to a width of 80 m. Since three cables are required for the final power system, it was decided that an at-sea test would be necessary to determine the feasibility of laying a cable to an accuracy of ±11 m on the seabed. In addition, the rough and steeply sloping bottom terrain, leading to the possibility of unacceptable cable spans on the bottom, required the cable be laid with controlled tension in the various portions of the route. Consideration of the high tensions to be encountered during laying, with 1900 m of cable suspended from the cable ship, led to a cable design with contra helically wound armor layers. This results in a cable which cannot be coiled in a tank, as in the typical case of submarine communications cables. The power cable being considered here requires storage on a revolving reel or turntable on the laying vessel, and must be kept under some tension at all times. The HDWC program developed an integrated control system to control the laying of this cable in these special conditions, and carried out an at-sea test program, laying the cable in the actual ocean positions, and recording data for use by the designers of the future commercial cable. CABLE ROUTE SURVEY The future permanent power cable will have a wet weight of about 27 kg/m and a diameter of about 12 cm. When laid over the sea bottom in the Hawaiian Islands, the cable will encounter bottom roughness due to old lava flows, submerged shorelines and reefs, escarpments and boulder fields. The cable may be laid over obstacles or suspended between obstacles in brief spans; the possibility of damage due to bending over obstacles, or fatigue caused over time by vortex-induced oscillations induced by tidal currents, must be avoided

Adaptive domain decomposition for unstructured meshes applied to the direct simulation monte carlo method

Numerical study of an adaptive domain decomposition algorithm based on Chebyshev tau method for solving singular perturbed problems

According to the impact of the submarine high voltage cable with a three-phase cable placed close to the route on submarine cable location detection, this paper clarifies basic detection methods for the submarine cable route, and also analyzes the distribution law of magnetic induction signal in the state of the adjacent multi-cable. Specific implemented measures of submarine cable location detection are summarized at the end of this paper. In addition, it solves the magnetic signal interference problem in the state of the adjacent multi-cable.

The strategic geographical location of Malaysia, with at least 60% of its shores are bordered with ocean, has high potential to sustain the country’s energy supply by harnessing energy from wave. However, the oceans stretch of which is suitable for wave energy generation needs to be accurately determined, with the sensitive and protected areas are taken into account. This study describes the methodology and more developed approach to determine the area not only with high wave energy but also its legality. The area is restricted at a minimum of 12 nautical miles from the coastline and the water depth is between 30 - 250 meters. Factors of oil and gas cable routing, marine parks, petroleum mining area, submarine cables and ports are considered in the analysis. Several GIS models constructed to facilitate the analysis. The methods of overlay spatial multi criteria analysis and clipping, based on the Geographic Information System (GIS) were employed. The determination of area with high potential for wave energy is vastly improved, producing a more reliable map. The results are the location of the marine energy potential in Malaysia shelf.

Simulations at physical quark masses are affected by the critical slowing down of the solvers. Multigrid preconditioning has proved to deal effectively with this problem. Multigrid accelerated simulations at the physical value of the pion mass are being performed to generate Nf = 2 and Nf = 2 + 1 + 1 gauge ensembles using twisted mass fermions. The adaptive aggregation-based domain decomposition multigrid solver, referred to as DD-αAMG method, is employed for these simulations. Our simulation strategy consists of an hybrid approach of different solvers, involving the Conjugate Gradient (CG), multi-mass-shift CG and DD-αAMG solvers. We present an analysis of the multigrid performance during the simulations discussing the stability of the method. This significant speeds up the Hybrid Monte Carlo simulation by more than a factor 4 at physical pion mass compared to the usage of the CG solver.