Real Time Quality Assessment for CORS Networks

Simon Fuller, Philip Collier, Allison Kealy

Department of Geomatics, The University of Melbourne, Melbourne, Australia.

DOI:                 

Abstract

The growing use of real time high accuracy Global Positioning System (GPS) techniques has resulted in an increase in the number of critical decisions made on the basis of a GPS derived position. When making these decisions mobile users require assurance that the GPS position quality meets their requirements. Providers of Continually Operating Reference Stations (CORS), whom mobile users are generally reliant upon, must also be able to assure users that their data meets agreed quality standards. Unfortunately, the realistic and reliable description of position and data quality is an area in which GPS has traditionally been weak. Research being undertaken as part of the Cooperative Research Centre for Spatial Information (CRC-SI) is attempting to address this problem by assessing and reporting on the quality of raw GPS observations in real time. This paper examines a number of existing approaches to assessing the quality of raw GPS observations and presents a conceptual architecture for the development of a real time quality control system.

Keywords

GPS, Quality, Real Time, Stochastic Modelling, CORS

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Barnes, J. B., N. Ackroyd, et al. (1998). Stochastic modeling for very high precision real-time kinematic GPS in an engineering environment. FIG XXI InternationalCongress. Commission 6, Engineering Surveys, Brighton, UK.
[2]	Brown, N., A. Kealy, et al. (2003). Quality control concepts for regional GPS reference station networks. SatNav 2003, The 6th International Symposium on Satellite Navigation Technology, Melbourne, Australia; 1-13.
[3]	Brunner, F. K., H. Hartinger, et al. (1999). GPS signal diffraction modelling: the stochastic SIGMA-D model. Journal of Geodesy 73: 259-267.
[4]	de Jong, C. D. (1998). A unified approach to real-time integrity monitoring of single- and dual-frequency GPS and GLONASS observations. ActaGeodaetica et Geophysica Hungarica 33(2-4): 247-257.
[5]	Estey LH, Meertens CM (1999). TEQC: The Multi-Purpose Toolkit for GPS/GLONASS Data. GPS Solutions, 3(1):42-49.
[6]	Euler, H. J. and C. C. Goad (1991). On optimal filtering of GPS dual frequency observations without using orbit information. Bulletin Geodesique 65(2): 130-143.
[7]	Fraser, R. (2004). SIRF Output Message ID 28. Personnel Communication.
[8]	Gurtner, W. (1999). Ashtech clock jumps in RINEX files. http://listserv.unb.ca/bin/wa?A2=ind9909&L=canspace&T =0&F=&S=&P=4271 . Accessed 3/11/04
[9]	Hartinger, H. and F. K. Brunner (1999). Variances of GPS phase observations: The SIGMA-E Model. GPS Solutions 2(4): 35-43.
[10]	Hofmann-Wellenhof, B., H. Lichtenegger, et al. (1992). GPS Theory and Practice. New York, Springer-Verlag Wien.
[11]	Hugentobler, U., R. Dach, et al. (2004). Bernese GPS Software, Version 5.0 DRAFT. Bern.
[12]	Jonkman, N. F. and C. D. de Jong (2000). Integrity Monitoring of IGEX-98 Data. Part I: Availability. GPS Solutions 3(4): 10-23.
[13]	Jonkman, N. F. and C. D. de Jong (2000). Integrity Monitoring of IGEX-98 Data. Part II: Cycle Slip and Outlier Detection. GPS Solutions 3(4): 24-34.
[14]	Kim, D. and R. B. Langley (2001). Quality Control Techniques and Issue in GPS Applications: Stochastic Modelling and Reliability Test. International Symposium on GPS/GNSS, Jeju Island, Korea.
[15]	Land Victoria (2004). Victorian GPSnet Website. http://www.land.vic.gov.au . Accessed 11/11/04
[16]	Rao, C. R. (1971). Estimation of Variance and Covariance components - MINQUE Theory. Journal of Multivariate Analysis 1: 257-275.
[17]	Richter, B. and H. J. Euler (2001). Study of improved observation modelling for surveying type applications in multipath environment. http://www.leicaatl.com/support/gps/Technical_papers/727 422en.pdf .
[18]	Rizos, C. (1999). Simultaneity considerations for GPS phase reductions.http://www.gmat.unsw.edu.au/snap/gps/gps_survey/chap6/ 638.htm . Accessed 2/9/04
[19]	Teunissen, P. J. G. (1990). An integrity and quality control procedure for use in multi sensor integration. ION GPS 90, Colorado Springs; 513-522.
[20]	Tiberius, C. C. J. M., N. F. Jonkman, et al. (1999). The Stochastics of GPS Observables. GPS World 10(2): 49-54.
[21]	Wang, J. (1998). Stochastic modeling for static GPS baseline data processing. Journal of Surveying Engineering 124(4): 171-181.