Research On RAIM Performance Compliance Verification Technology For Beidou Airborne Equipment

BeiDou Navigation Satellite System(BDS)is improving and has become one of the four core constellations in the world.With the continuous improvement of BDS performance,it is imperative for BDS to be used in civil aviation.Therefore,it is of great significance to study whether the BDS airborne equipment meets airworthiness requirements.As one of the four core indexes of the navigation system,integrity is related to life safety.Therefore,the examination of integrity performance is an indispensable part when the airworthiness verification is conducted for the BDS airborne equipment.In this thesis,the RAIM performance compliance verification Technology applicable to the Beidou airborne equipment are researched by referring to the performance test methods of RAIM algorithm for airborne equipment in the Technical Standard Oder(TSO)-C129 A and the Standard document RTCA DO-208.The main contents are as follows:First of all,the time/coordinate system and the conversion method between different systems are briefly introduced in this thesis.The Beidou satellite position and receiver position solving algorithm are summarized,and the feasibility of the algorithm is verified.Secondly,the equivalence of the three “snapshot” algorithms based on the analysis of three RAIM algorithms are illustrated,selected the method of removing the bad satellite geometry,compared the two ways of calculating the detection threshold,proposed a baseline BDS RAIM scheme based on the three "snapshot" RAIM algorithms,and discussed the RAIM algorithm which augmented with barometric altimeter aiding.Then,the RAIM performance compliance verification technology for Beidou airborne equipment is analyzed in detail,including off-line software simulation tests as well as on-line bench tests.The technology is used to test the least square residuals method,and the result shows that the the least square residuals method meets the integrity requirement of the nonprecision stage.Finally,According to the RAIM performance compliance verification technology for Beidou airborne equipment,the RAIM Performance Compliance Verification system is developed with MATLAB software,introducing each module of the system in detail and giving the operation examples.