Evaluation Of DME/Secondary Surveillance Radar On Beidou Airborne Equipment

The analysis of the performance changes of Beidou receiver under the influence of different types of interference signals is the premise of Anti-jamming technology research,and it can provide the necessary theoretical basis for the research of interference signal monitoring and suppression algorithms.The Beidou receiver's on-board electromagnetic environment is gradually becoming more complicated.Analyzing and evaluating potential interference sources such as on-board electronic equipment and fixed aviation transmitters is a prerequisite for studying satellite navigation radio frequency interference mitigation techniques.By referring to the reference documents RTCA DO-235 B and RTCA DO-229,which are used to evaluate the impact of Radio frequency interference(RFI)on GPS L1 and GPS L5,evaluating the performance of Beidou airborne receiver and RFI electromagnetic environment and analyzing the influence of two typical interference sources of Distance measuring equipment(DME)and secondary surveillance radar(SSR).The main contents are as follows:First,the aviation risk and the impacts of RFI are analyzed.Based on the RFI analysis model of the interference source-path-receiver,a link budget method is selected that covers continuous interference and high and low power pulse interferences.Analyzed and evaluated the parameters required by the model: RF front-end parameters,six aviation RFI conflict scenarios,and major potential interference sources.It is concluded that DME and SSR may produce continuous wave interference and pulse interference.Second,the Beidou B1 I signal structure and the characteristics of the Beidou B1 I signal spreading code are briefly introduced in this thesis,the frequency of the worst spectrum line of the published Beidou civil spreading code and the corresponding amplitude are summarized,and it is verified by simulation.Then,a typical interference signal model is established for analyzing the impact of typical interference signals on the carrier-to-noise ratio,acquisition,and tracking performance of Beidou receiver and simulation verifications are performed.Analyze the interference thresholds of Beidou receiver,including continuous wave interference,band-limited noise interference,and pulse interference.Finally,the working principle of DME and SSR equipment and potential impacts on Beidou airborne equipment are analyzed in detail.Finally,satellite navigation RFI mitigation techniques are given.Finally,the working principles and the aviation operation roles of DME and SSR equipment,and their potential impact on Beidou airborne receivers are analyzed in detail.And satellite navigation RFI mitigation techniques are given.