A novel UKF based scheme for GPS signal tracking in high dynamic environment

Unscented Kalman filter (UKF) based methods have been developed for the tracking of GPS L1 signal. Optimal Kalman filtering theory makes it possible to maintain locking with large Doppler frequency shift when the receiver works in high dynamic environment. A novel UKF based carrier tracking loop with high accurate tracking performance is put forward, where a frequency fast pull-in technology is performed to ensure the filter converge fast and another two different carrier amplitude estimation methods are included to make the dynamic model complete. The relationship between the noise parameter of UKF and the equal loop-bandwidth is also studied. Based on this novel loop and carrier-aiding technology, a joint carrier aiding and code phase extracting from the estimation results of the UKF for code tracking is analyzed. Simulation results show that the carrier tracking loop works steady in high dynamic situations, and the pseudo-code tracking precision is improved significantly.