The Study Of VDES High Accuracy Differential Service System Based On CORS System

As BeiDou navigation system is recognized by IMO,the demand of high accuracy positioning technology in the navigation area is increasing.Difference enhancement technology is a common way of high accuracy positioning technology.With the research and birth of VDES,a new generation of maritime communication system,it is feasible to improve the ship positioning accuracy in VDES by increasing the auxiliary positioning data.Based on this,this paper studies the high accuracy VDES differential service system based on CORS system,which has positive practical significance both in terms of technological innovation and application practice.Firstly,this paper introduces CORS system and related theory of CORS system virtual difference reference station Based on this,the VDES difference user model for improving the positioning accuracy of VDES system is proposed.The model includes VDES broadcast difference user model and VDES addressing difference user model.In this paper,the specific structure of the model is described,and the localization algorithm and the error are analyzed theoretically,and the format and relative standards of the specific transmission data involved in the model are expounded.Based on the above research,the VDES differential broadcast model is selected as the theoretical model of application system.Based on the requirements analysis of the VDES differential service system based on CORS system,the overall architecture and software service framework of VDES differential service system are designed Three parts of system included VDES differential service center software,VDES base station difference module and VDES ship station difference module are designed in detail.Among them,VDES base station difference module and VDES ship station difference module are embedded in VDES base station equipment system and VDES ship station equipment system as function module.Based on the above system platform,the performance and precision of the system are tested in detail.The results show that the channel load of AIS channel in the system is theoretically analyzed and simulated,and the optimal transmission interval is determined.In the accuracy test of the differential service provided by the system,Dalian yellow white mouth base station is selected as the test site.This paper tests and analyzes the positioning accuracy of system difference service by dynamic test and static test.The results show that the accuracy of static positioning and dynamic positioning is 0.76m(2 ?)and 1.46m(2 ?)based on the difference service system,which is better than the normal single point positioning accuracy.