The Design And Realization Of The Data Service System Of Electronic Chart On Multi-platform

The development and application of electronic chart and its applicable system are hot issues for modern navigation field. By the data service system of electronic chart, necessary support and guarantee for activities like ship sail and control etc are provided. And the functions like chart data search, query and download etc for client group are guaranteed also. Meanwhile, it provides data share service to multi-platform electronic chart system client ends. As an important component of application system, electronic chart data server is considered as the bridge linking inside and outside. Taking electronic chart data service system as engineering background, the design and realization of electronic chart information communication system are accomplished.The demands of electronic chart data service system are analyzed, and the designs of project, function module and reliability are also accomplished. The realization of various modules is explained in detail. Apply IP unicast and multicast communication technology into concurrent server based on Linux by concurrent C/S pattern and SOCKET technology. This theory can solve the information block problem caused by multiple ends visiting server simultaneously. Guarantee the reliable transmission between internet information and information processing devices to solve the reliable issues about information transmission. Use the mature internet TCP/IP technology to realize the data share service based on multi-platform cross Linux and VxWorks. The problem of scattering chart resources is solved. By analyzing cross chain table structure of electronic chart index, the quick search function to data of electronic chart by selecting area and scale is accomplished.Finally, the working environment of electronic chart data service system is simulated and the integrated communication system network of electronic chart with multiple client ends is established. The test to the whole communication system is also accomplished. After analyzing the TCP/IP agreement, the pack loss position and the reason of pack loss are detected. And the solution is given. The test results indicate that the electronic chart data service system with reasonable design and good function meets the demands of information support and guarantee of the electronic chart data service system.