Research On Key Technologies Of Scanning And Positioning Based On UWOC

Modern land communication technology is very mature,and underwater communication technology has better development prospects.The premise of achieving stable underwater communication is to clarify the position information of both parties in the communication,so the positioning system is very important for the development of underwater communication.Considering the erosion of water flow,underwater communication technology is mostly based on the development of wireless technology.Among a variety of underwater wireless communication technologies,underwater acoustic communication and optical communication are two main branches.The development of underwater acoustic communication technology is relatively mature,but as people continue to intensify their exploration of marine resources and their increasing demand for marine resources,the low code rate and narrow bandwidth of underwater acoustic communications are no longer able to meet people's needs.In contrast,light has a "transmission window" under water,which opens up another path for the development of underwater wireless communication technology.Compared with underwater acoustic communication,underwater optical communication has the characteristics of large channel capacity and strong anti-interference ability,so underwater laser communication has become a research direction with great development potential at present.However,due to the difficulty of operating in the underwater environment,the current research on underwater communication mostly focuses on the analysis of channel characteristics,and there is less research on underwater optical positioning.Based on the modern optical propagation theory model,an underwater laser scanning and positioning system is constructed to explore the exact location of leakage from underwater oil and gas pipelines.The work and innovation of the thesis are embodied in three aspects.Firstly,the underwater anchor node network structure is constructed by rational lying the underwater node,the improved underwater beam distribution characteristic model is proposed on the basis of the traditional underwater beam distribution model,combined with the water quality influencing factors and the receiving end detection threshold factor,and the three-dimensional dynamic restricted node water flow model in line with the underwater scene is proposed on the basis of the traditional two-dimensional water flow model.Secondly,after setting up the operating environment of the system,the paper designs a multi-point scanning scheme,and filters out reasonable scanning parameters by the influence of scanning rotation factors so that the laser source can capture the underwater target node with a capture probability of more than 70% in 10 seconds,and obtain the corresponding rotation angle information when it is captured,so as to transmit reliable angle information for positioning for subsequent positioning.Finally,after the angle information of the target node,the system uses two laser sources with different beam scatter angles to send the laser in the direction of the target node,according to the laser intensity received before and after combined with the beam distribution function of the underwater laser to obtain the distance between the target receiving node and the transmit node,and then obtains the position information of the target node according to the angle information obtained by the scanning phase,so that the positioning accuracy of the system is not more than 5dB in the distance of 20 meters.To realize the purpose of underwater laser positioning,it lays a good foundation for underwater optical communication.