Performance Analysis of Precise Point Positioning Using Rea-Time Orbit and Clock Products

Yang Gao, Kongzhe Chen

Department of Geomatics Engineering, University of Calgary, Calgary, AB, Canada.

DOI:                 

Abstract

The real-time availability of precise GPS satellite orbit and clock products has enabled the development of a novel positioning methodology known as precise point positioning (PPP). Based on the processing of un-differenced pseudorange and carrier phase observations from a single GPS receiver, positioning solutions with centimeter to decimeter accuracy can be attained globally. Such accuracy can currently be achieved only through differential processing of observations acquired simultaneously from at least two receiver stations. The potential impact of PPP on the positioning community is expected to be significant. It brings not only great flexibility to field operations but also reduces labor and equipment cost and simplifies operational logistics by eliminating the need for base stations. This paper will address issues related to precise point positioning and perform data analysis to assess the performance of different application solutions from PPP using real-time precise orbit and clock corrections. They include the discussion of an algorithm for un-differenced data processing, error source and mitigation, and critical elements related to real-time GPS orbit and clock products. Numerical results will be presented to show the positioning accuracy attained with datasets acquired from different environments using real-time precise orbit/clock products currently available. Features of a software package that has been developed at the University of Calgary for precise point positioning will also be described.

Keywords

GPS, Precise Point Positioning, Undifferenced, Precise Orbit and Clock

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Bar-Sever YE, Kroger PM and Borjesson JA (1998): Estimating Horizontal Gradients Of Tropospheric Path Delay With A Single GPS Receiver. Journal of Geophysical Research, Vol. 103, No. B3, pp. 5019-5035.
[2]	Chen G and Herring TA (1997): Effects Of Atmospheric Azimuthal Asymmerty On The Analysis Of Space Geodetic Data, Journal of Geophysical Research, 102, No. B9, 20, 489–20,502, 1997.
[3]	Gao Y, Skone S, Chen K, Nicholson NA and Muellerschoen R (2004): Real-Time Sensing Atmospheric Water Vapor Using Precise GPS Orbit and Clock Products, Proceedings of ION GNSS 2004, Long Beach, California, September 21-24, 2004.
[4]	Gao Y, Chen K and Shen X (2003): Real-Time Kinematic Positioning Based on Un-Differenced Carrier Phase Data Processing, Proceedings of ION National Technical Meeting, Anaheim, California, January 22-24, 2003.
[5]	Gao Y and Shen X (2002): A New Method for Carrier Phase Based Precise Point Positioning, Navigation, Journal of the Institute of Navigation, Vol. 49, No. 2.
[6]	Héroux P (2004) personal communication.
[7]	Kouba J and Héroux P (2001): GPS Precise Point Positioning Using IGS Orbit Products, GPS Solutions, Vol.5, No.2, pp. 12-28.
[8]	Larson K, Levine J, Nelson L and Parker T (2000): Assessment Of GPS Carrier-Phase Stability For Time-Transfer Applications, IEEE Trans. Ultrason., Ferroelect., Freq. Control. Vol. 47, pp. 484–494.
[9]	Muellerschoen RJ (2003): personal communication.
[10]	Petit G, Jiang Z, White J, Beard R, and Powers E (2000): Absolute Calibration Of An Ashtech Z12-T GPS Receiver. GPS Solutions, Vol 4, No. 4, pp. 41–46.
[11]	Radiometrics Corp. (1999): WVR-1100 Total Integrated Water Vapor and Liquid Water Radiometer Manual.
[12]	Zumberge JF, Heflin MB, Jefferson DC, Watkins MM and Webb FH (1997): Precise Point Positioning For The Efficient And Robust Analysis Of GPS Data From Large Networks. Journal of Geophysical Research, Vol. 102, 5005-5017.