Analyze and research the integrated navigation technique for GPS and pseudolite

摘要

To heighten the stability and precision of GPS positioning, the integrated navigation system for GPS and pseudolites (GPS/PL) was set up. The nonlinear equation of pseudo-distance measurement was linearized by Taylor series expansion, but it can't find any influencing factors of the truncation error. A new deducing method of the linear equation of pseudo-distance measurement was put forward, and some influencing factors of the truncation error were found and the nonlinear degree was defined. By the comparison of the nonlinear degree for GPS and pseudolites, the truncation error of pseudolite was found much larger than that of GPS navigation during the linearization. In allusion to the stable flight state of aircrafts, the nonlinear system equations of an integrated navigation system for GPS and pseudolites (GPS/PL) were set up, and the unscented Kalman filter (UKF) was used to estimate the navigation parameters to solve the nonlinear problems of PL. The simulation results showed that the maximum positioning error is 14 meters, and the mean value is 7 meters. Thereby, the pseudolites make the enhancement for the positioning precision and system stability of GPS navigation.