Research On GNSS Signal Ranging Preformance Evaluate Technology Based On Narrow-beam Antenna

Timing,ranging,navigation and positioning achieved by satellite navigation systems are based on the navigation signal.Signal quality not only reflects the satellite working state,but also directly affects the navigation application of all kinds of navigation.Therefore,navigation signal quality monitoring became an important link in in orbit test,long term monitoring and modern design of the system.At present,the evaluation parameters of navigation signal quality monitoring is related to typical assessment parameters of communication systems.But,the navigation signal has its own characteristics.The system is ultimately provide application services like positioning,timing,speed.Application performance is the fundamental to measure the quality of service of satellite navigation system.Navigation signal quality monitoring should also be closely linked to the user application performance.In this paper,starting from the actual demand of navigation signal quality monitoring,a preliminary study of issues related to the ranging performance of the navigation signal was conducted.The methods of evaluating ranging performance and navigation signal distortion and its effects on ranging were studied in the first part.Firstly,the structure characteristics of navigation signal and all kinds of modulation were introduced.The evaluation process of ranging performance was proposed.The typical signal processing algorithm and algorithms designed for BOC signals were introduced.Evaluation methods of ranging performance were expounded.Finally,the signal distortion model was introduced.Also the effect of different signal distortion on the ranging performance was evaluated.Satellite orbital prediction methods based on the narrow beam antenna were studied in the second part.In order to avoid the effects of multipath and interference.The narrow beam antenna which has a high gain was needed to receive the navigation signal before testing the navigation signal range performance.The servo system predict the elevation and azimuth to tracking satellite automatically.This paper presents several methods of satellite orbit prediction.The prediction precision of angle was compared.The results indicated that,not only the precision of SDP4 model can meet the required standard,but also this model can be durable.Therefore,it is practical and applicable.In the third part,the real-time tracking of narrow beam antennas for satellite navigation was realized with SDP4 model and the ranging performance of in-orbit signals of all systems are evaluated combining with the research of the evaluated method.The testing method was been verified.The evaluation results indicated that,under the current condition,the ranging performance of the Beidou system was slightly better than the other systems.Finally,the research work and the application are summarized.The future studies needed to be carried out are discussed.The contents of this paper can be applied directly to the navigation signal source test and on orbit satellite signal quality real-time monitoring,which has a great application value.