Research And Implementation Of Differential And Integrity Algorithms On BDS GBAS

The satellite navigation system used in civil aviation, can effectively enhance flight safety and efficiency. Therefore, the satellite navigation system as a primary means of navigation used in precision approach and landing aircraft, is the future trend of navigation. Since civil aviation navigation use only standard positioning navigation system, it is difficult to meet in terms of performance positioning accuracy, continuity, integrity and availability, etc., it must be accompanied by certain enhanced system to improve the performance of satellite navigation. Enhanced system is divided into three parts SBAS, ground-based augmentation system ABAS. Satellite-based Augmentation System is a wide coverage augmentation system, enhanced user transmitter receives information from the satellite-based; ground-based augmentation system to enhance the system to enhance the user receives information directly from land-based transmitters; ABAS is available onboard information and information obtained from other GNSS elements integrated or enhanced an enhanced system. This paper studies the ground-based augmentation system parts.Ground-based augmentation systems including Beidou satellite systems, environmental systems, subsystems ground, airborne subsystem four modules. This paper describes part of the ground subsystem. The ground subsystem information and passing through the receiving satellite navigation signals, get the Beidou satellite navigation system navigation message data, observational data, system monitoring data, to a data processor, the data processor according to the monitoring data, navigation message data to achieve integrity monitoring the satellite navigation system and the formation of integrity monitoring parameters. According to the precise location of the ground station through differential algorithm processing is corrected each satellite pseudorange and carrier phase, while together forming a differential correction information based on satellite integrity and approach parameters are handled. At the same time according to which the ground subsystem airport location information, the case of forming a ground station the glideslope information des ign parameters, FAS information parameter, and ultimately the above parameters in the form of a variety of information on the air broadcast messages broadcast to pack airspace around the airport.Ground based augmentation systems architecture Beidou system proposed is suitable for the Beidou satellite navigation algorithm flowchart and work process flow; differential correction amount of research to define the Beidou proposed differential correction algorithm applied to Beidou satellite navigation, includ ing carrier-smoothed, differential correction, differential correction average, differential correction errors, and B values, to enable it to meet the requirements of the radio transmission capacity, the formation of the Big Dipper differential parameter definitions and values norms; definitions and methods of research integrity monitoring forth the Beidou satellite navigation intact monitoring algorithm, consider differential and define the integrity of the correction amount of multi-system, can meet the transmission capacity and processing delays impact on the positioning error, the formation parameter defines the integrity and value specification. Through enhanced research-based foundation Beidou system to solve the positioning accuracy and integrity problems, make the satellite navigation can be used in civil aviation, to achieve the flexibility and arbitrary route. For the development of civil aviation has provided technical support.