Submarine Cable Comprehensive Monitoring System Software And Vibration Source Location Method

In order to design an effective and reliable submarine cable safety monitoring system,it is necessary to conduct three-dimensional real-time monitoring of the submarine cable environment.This can achieve long-term stable operation after a single deployment,with low maintenance time and economic costs.This thesis utilizes DAS and BOTDA sensing devices widely used in the optical fiber sensing field,combined with equipment such as Automatic Identification System,Short Message Service and video monitoring on the sea surface,to realize a submarine cable monitoring system for comprehensive three-dimensional monitoring of the submarine cable environment.At the same time,the vibration source localization method based on DAS is explored,enabling the system to obtain specific location information of vibration events,further enhancing the early warning capability of submarine cable safety issues.The main research content is divided into three parts:(1)Aiming at the current problems of submarine cable safety,this thesis analyzes the Functional requirement of submarine cable monitoring,and designs a Software architecture that meets the actual requirements of submarine cable monitoring.On this basis,in response to the issue that the fiber optic sensing equipment in the system can only provide axial positioning of submarine cables for safety events,a survey was conducted on the current status of vibration source positioning methods for DAS equipment in the system hardware.(2)Designed and implemented a comprehensive monitoring system for submarine cables based on B/S architecture.By receiving,processing,and storing data from hardware devices such as DAS,BOTDA,AIS,and visualizing various information in the form of web pages according to the system’s functional requirements,large-scale passive monitoring of submarine cable safety in the sea area is achieved.And the practical value of this system was verified through on-site deployment testing in actual submarine cable monitoring environments.(3)Research on vibration source localization of important hardware equipment DAS in the system using TDOA algorithm.By comparing the principles and applicable conditions of the classic DOA algorithm and TDOA algorithm in array signal processing,a TDOA algorithm that is more in line with the monitoring environment of submarine cables was selected for the vibration source localization of the DAS system.In order to reduce the impact of factors such as vibration signal distortion during propagation on the accuracy of TDOA calculation,credibility screening was conducted on the channel signals collected by the DAS system,Finally,the feasibility of TDOA algorithm in vibration source localization based on DAS was verified through simulation and experiments,laying the foundation for its future application in the submarine cable comprehensive monitoring system.