The Study On Automatically Modifying Electronic Electronic Chart Based On Internet

With reference to existent corrective methods ,the paper is intended to design new automatically corrective methods of electronic chart applying the technology of net and database . The methods keep the merits of the existent corrective methods and abandon their shortcomings, show variational information of sea in electronic chart accurately and rapidly , provide reference for users and help them make decision.The paper mainly introduces existent corrective methods in the first chapter , analyzes merits and shortcomings synthetically and puts forward author's methods at last ;explains rules of Notices to Mariners in second chapter; introduces the course of establishing the database of Notices to Mariners and the application of client/server structure in the third chapter; narrates the management and application of Notices to Mariners s database in the fourth chapter ;introduces the establishment of Notices to Marnier's the internet site ,page and content in the fifth chapter ;modifys the local database according to data downloaded from net and show in the sixth chapter.In conclusion , Notices to Mariners's database is published to the internet site .Users can get Notices to Mariners at any moment through Internet and automatically modify the local database .The methods make full use of the advantages of internet.