The GPS position based on carrier phase measurement is produced and developed for the exaltation of positioning accuracy. However, in practice, carrier phase observations often include various errors besides essential parameters. Sometimes even satellite signals may be temporarily interrupted and lead to cycle slips. Most of errors can be eliminated with differencing of carrier phase observation. But phase center offsets (PCOs) are a key source of errors in GPS precise measurements and hardly eliminated or weakened by difference methods. Meanwhile as a gross error, cycle slips decreases badly positioning accuracy but can't remove by differencing approach. For all this, based on the feature of cycle slips and time series analysis theory, a quickly and convenient method of eliminating various errors, detecting and correcting cycle slips and PCOs is presented in this paper for high accuracy positioning solution. The key of this method is to build difference series between carrier phase observations of satellites, stations and epochs. These difference series can be used to eliminate various errors implied in observation data, and highlight the features of cycle slips. Based on the time-series analysis theory, the model of difference series of carrier phase observation data is built, cycle slips can be quickly detected by the stability of this time series. At last, the experiment results show that the new method can not only be suitable both for static and dynamic measurements of dual-frequency GPS receivers, but also can eliminate most measurement errors of dual-frequency GPS receivers, improve the efficiency of detection and correction of PCOs and cycle slips less than 1 cycle.
['Zhige Jia', 'Zhengsong Chen', 'Dijin Wang', 'Pengfei Yu']
Time series analysis of carrier phase differences for dual-frequency GPS high-accuracy positioning