The Design And Implement Of The Distributed Ship Real-time Dynamic Trailing System

With the maturity of the new technology of computer network and communication, also with the prevalence for public uses of the technology of GPS, each technologies for tracking and locating ships have come to adapt to the requirement of the applications. Applying a few advanced ideas and technologies other than ago to develop a useful ship real-time dynamic trailing system is our study direction.It is concluded that the limit of systems developed by the traditional methods is that they are standing alone, occluded and lacking the extensibility, adaptabilities and flexibilities. That's difficult for it to adapt the changing environment and the cost of enhancement and maintenance is very high. Thus the thesis have applied the object-oriented ideas and CORBA-based infrastructure in our study. The thesis make the system such a wide openness and extendibility that it is guaranteed to meet each application.The thesis have developed a series of components in the network, co-operating on the base of CORBA infrastructure. They use the common interfaces to access each other and hide the details of implement of their own. So they are independent each and establish a relationship only when they need the services provided by the others.According to the courses of locating data acquisition, storing and using, The thesis describe the functions of the components and the courses of realization. Combining with the mechanism of data acquisition, The thesis study and compare the modem ways of communication, and choose the CDPD communication network to transfer the out-bursting information from the ships in real-time mode. During the course of data storing, The thesis apply the three-tier database structure based on network, insulate the access between the client and the server by the middle tier, so as to lighten the load of the network traffic and database server. The model ofdatabase is adopted the thought of object-oriented, and the thesis give a demonstration of the entity of ship. The main purpose to track the information of ship is to locate the ship so the thesis discuss the method to locate the ship on e-chart. Finally, The thesis discuss briefly GPS positioning and map match.