New Gnss Navigation Signal Deformation Detect And Analysis

Global navigation satellite system is an outstanding representative of modern technologies, and has brought great changes to the world. Both the advanced national defense industry and the lives of ordinary people rely on the navigation service of satellite navigation system. The faults and errors can not always be avoided during the application of navigation system, so it is important to research on the detection of the faults in navigation signals.The positioning precise of GPS SV19 navigation satellite deteriorated in 1993,and doctor R.Eric Phelts established “Second-Order Step” threat model in 1999 to describe that kind of “evil waveforms” which lead to the deterioration of positioning precise. Since then, Eric and researchers of GPS laboratory has made more in-depth study on “Second-Order Step” threat model. Beidou navigation satellite system is building up, so it is important to study on the “Second-Order Step” threat model of the new generation of satellite navigation signals.This thesis started with the research of “Second-Order Step” threat model, and established the AltBOC navigation signal detection and measurement system to detect the evil waveforms of navigation system. In this way, we can monitoring the satellite system in real-time, and take measures in time to deal with the abnormal situation.This thesis established the navigation signal fault detection index set, then select the indexes which are sensitive to the characteristics of “Second-Order Step” anomalous signal, so that we can analyze the signal in relate domain time and frequency domain and modulation domain.This thesis also detected the “Second-Order Step” anomalous AltBOC signal with the established platform and analyzed the distortion characteristics to draw the conclusions.This thesis has made more in-depth research on “Second-Order Step” threat model standing different angles with previous studies in an ideal to detect the “Second-Order Step” anomalous rather than analyze the characteristics of “Second-Order Step” anomalous signal, established the navigation signal mutation detection system and platform to monitor the satellite signals in real-time, and analyzed the test results of “Second-Order Step” threat model to sum up the characteristics of various types of mutation and draw the conclusions.