Research On Tracking Loop Design And Filtering Method Of GNSS/INS Deep Integration

GNSS/INS(Global Navigation Satellite System/Inertial Navigation System) integratednavigation system not only enhances the anti-jamming ability of satellite navigation receiver,but also can correct the navigation parameters of INS. GPS/INS integrated navigation hasthree stages, that is, loose integration, tight integration and deep integration (ultra-tightintegration).INS is the main system in the GPS/INS loose integration, in tight integration anddeep integration, the Doppler shift information obtained by INS is introduced to GPS signalacquisition and tracking loop, therefore,the structure of receiver need to be changed.The thesis takes GPS for instance in this papaer, analyzes the basic working principle ofGPS/INS integration sub-system, pseudrange measurement principle and carrier phasemeasurement principle are introduced based on GPS signal instructure; the thesis takesStrapdown Inertial Navigation System (SINS) for instance in INS, its working principle isintroduced. The method of attitude determination and the error equation of SINS are analyzedin detail, which lay a foundation to build the filter equation of GPS/INS integration navigation.Then, it analyzes the working principle of the GPS receiver tracking loop, the tracking errorcharacteristics of code Delay Lock Loop(DLL) and carrier Phase Lock Loop(PLL) arestudied,the relationship of carrier dynamic stress error、noise error and loop bandwidth aresimulated. The tracking loop characteristic of receiver which is aided by INS was also studied,in code DLL adding by INS information, a Gaussian Code Phase Discriminator is designed toimprove the tracking accuracy when receiver working in muti-path environment.A vector tracking loop is studied base on traditional receiver tracking loop. Code phaseerror and carrier phase error are caculated, then these errors are no longer directly as thecorrection which are feedback to local signal generator to adjust the copy signal frequency,but are input to the extend kalman filter to calculate position and velocity of carrier, the unitLine-Of-Sight(LOS) between receiver and visible statellites are updated. Then thepseudorange and pseudorange-rate are predicted at next time, at the same time, newpseudorange error and pseudorange-rate error are got through calculating with received signal,the vector tracking loop is finished. GPS/INS deep integration was researched based on vectortracking loop, the model of navigation filer is analyzed and the simulation system of GPS/INSdeep integration is builded, after the carrier contrail is simulated,the position error is studiedby GPS and GPS/INS deep integration, which indicates the method of GPS/INS deepintegration based on vector tracking is available.