Research On Technologies Of Tracking Dynamic GNSS Receiver

At present, there are four main global navigation staellite system(GNSS) in the world,that are American GPS(U.S.A.), European GALILEO, Russian GLONASS and ChineseCOMPASS. GNSS makes the navigation satellite system have unprecedented nature andadvantages, however, when the navigation receiver is assembled in the highly dynamic carrier,the relatively higher velocity, acceleration, and jerk between the receiver and the satellite willcauses the received GNSS signal carrier phase a large Doppler shift, first-order andsecond-order derivatives of Doppler shift. So, the navigation receiver used in the highdynamic environment needs high dynamic carrier tracking scheme. The thesis mainlyanalyzes the design of the carrier tracking loop scheme in the high dynamic receiver.The thesis takes GPS for instance, analyzes the strcture and character of GPS signal,studies and summarizes three acquisition algorithms, and analyzes their principle of, at lastcompares the algorithm’s computation and their cost of implementation. It focuses on thedesign of the GNSS receiver tracking loop, including the design of carrier tracking loop andcode tracking loop. In order to solve the tracking accuracy of the traditional phase-lockedloop(PLL) under the dynamic environment, it studies a new adaptive two-stage Kalman filtercombining the adaptive fading Kalman filter and the two-stage Kalman filter, and proposes anew method of calculating fading factor by innovation covariance, which compensates theeffect of inaccuracy information by rescaling of the error covariance with the fading factor,and makes the filter remain close to optimal when the system model is incomplete or thestatistical properties of the noise is inaccurate. It proposes a design scheme of high dynamicGPS carrier tracking loop based on adaptive two-stage Kalman filter. It uses non-coherentearly-late cade tracking loop for code tracking algorithm, in order to solve the conflictbetween the tracking accuracy and dynamic tracking capacity, it adopts the technique ofcarrier assisting to eliminate the direct dynamic effects on tracking loop, and improvestracking performance of the loop.It simulates and verifies the designed carrier tracking loop and code tracking loop,designs a typical high dynamic simulation environment, and compares the designed carriertracking loop method with the traditional third-order PLL method, then the simulation resultshows the proposed scheme evidently improves tracking accuracy of PLL comparing thetraditional PLL and makes the tracking accuracy reach9.28Hz. And with the assitance ofcarrier loop, code tracking loop eliminates the direct dynamic effects on tracking loop, with better tracking result.