The New Navigation System, Automatic Dependent Surveillance Broadcast Technology Research

CNS/ATM system has been practiced and applied by ICAO step by step.The system is a global system composed by communication,navigation,surveillance and roboticized ATM. It is mainly a satellite-based global communications, navigation and surveillance with automated air traffic management systems,including infrastructure of communications, navigation and surveillance systems, and air traffic management made up of management system, facilities and application software.A notable feature of CNS/ATM system is the automatic dependent surveillance (ADS) technology, especially automatic dependent surveillance-broadcast(ADS-B) technology based on the data link communication technology.The paper describes the research background and the value of project, describes the course of development and principles of CNS/ATM,introduce the development and application of automatic dependent surveillance(ADS); showes the principle of ADS-B and application of data link technology; mainly discusses how to choose the ADS-B system data link technology in the development of large aircraft,also application program of used data link technology is introduced.In the research process of project, we raises ADS-B by describing the production, development, component, feature and major technology used in CNS/ATM.Data link technology is the core technology of ADS-B, now ADS-B data link technologies recognized and implemented by the ICAO include Secondary Surveillance Radar S-mode(SSR-S), VHF Data Link Mode 4 (VDL4) and Universal Access Transceiver ( UAT).Considering advantages and disadvantages of 3 technologies, and the characteristics of military large aircraft development projects, S mode and VDL 4 are our research focus. Based on the Air Traffic Control SSR, SSR-S can be modified at little cost in civil aircraft.While VDL4 is based on VHF communication technology,using GFSK modulation and STDMA networking,can support the air - ground, air - air, broadcast and point to point communications services,its technology is more mature and advanced for large-scale Chinese military aircraft requirements.At last,the paper studies VDL4 system structure, system timing, time slot selection, site and channel management, collaborative technology application.The project researches and studies with the Military Large aircraft development, by referencing current military and civilian data link technology. We proposes VDL4 as the application direction of military large aircraft ADS-B system. Then we design a reasonably practicable applications program according to the actual circumstances,achieved the demand and gained good performance expected before.