Key Technology And Practice Of Satellite Navigation Signal Performance Evaluation And Monitoring

Bei Dou navigation application has been playing an important role in national security,economic construction and people's everyday life since its deployment.Bei Dou navigation system can provide high accurate positioning service,and the reliability and stability of its service makes Bei Dou outstanding in high quality satellite navigation applications such as aviation navigation.Bei Dou is usually known as ‘high applicable navigation'.The system's applicability mainly depends on two factors.The first one is the signal quality of the navigation satellite,and the second one is the performance of the receiver and other assistant tools.This thesis studies the monitoring and evaluation of quality of satellite signal.The main contributions are the followings: 1)The signal of the four main satellite navigation systems are described and analyzed extensively.Simulation and analysis is performed for the recently proposed BOC(Binary Offset Carrier),MBOC(Multiplexed Binary Offset Carrier)and AltBOC(Altermate Binary Offset Carrier)in both time domain and frequency domain.2)Signal abnormity caused by non-idealism of satellite payload is studied.2OS model is established,and analysis of digital circuit abnormity TMA,analog circuit abnormity TMB and mix of digital and analog circuit abnormity TMC are performed.The three abnormal signals are generated on genuine signal processing board,and the spectrum of the abnormal signal are measured and analyzed.Also,the influence on the positioning accuracy is evaluated.3)A set of evaluation methods in time domain,frequency domain,correlation domain and measurement domain based on received signal are proposed.The corresponding parameter estimation and evaluation algorithms are designed,and these algorithms have been applied in Bei Dou III system.4)Post-processing programs for signal evaluation is developed and deployed in iGMAS in Shijiazhuang.Bei Dou signal is received by high gain antenna and its quality is evaluated.The results show that B1,B2,and B3 navigation signal has abnormity less than 0.7 ns,and variance less than 5 ns.Absolute change in power spectrum is less than 0.3dB,and the standard variance is less than 0.6dB.S-curve offset is less than 0.5ns(main lobe width).Code phase coherence among B1 I,B2I and B3 I is less than 3ns.Coherence of code carrier phase is less than 0.1 degree.The above results have applied in GNSS evaluation system.