Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-24T02:36:51.697Z Has data issue: false hasContentIssue false
  • English
  • Français

A New High Precision Wide Area DGPS System

Published online by Cambridge University Press:  23 November 2009

V. Ashkenazi ,
C. H. J. Chao ,
W. Chen ,
C. J. Hill  and
T. Moore
T. Moore
Affiliation:
(Institute of Engineering Surveying and Space Geodesy, The University of Nottingham)
Get access Rights & Permissions [Opens in a new window]

Extract

This paper describes an advanced method, and the corresponding algorithms, which could provide a high precision Wide Area Differential GPS (WADGPS). The service would be suitable for single or dual frequency users, and could be introduced with very few reference stations. The two main components of the service are a precise, near real-time orbit determination of the GPS satellites, and an accurate estimation and modelling of ionospheric and tropospheric effects. Broad principles of the processing algorithms and results of both simulation and real data tests are described. User positioning accuracies of better than 2·5 m (r.m.s.) in plan and 3·0 m (r.m.s.) in height are achieved by both single and dual frequency scenarios.

Wide Area Differential GPS (WADGPS) is being developed to overcome the main drawbacks of conventional or Local Area Differential GPS (LADGPS), where positional accuracy of a user degrades as the reference-to-user separation increases. The spatial decorrelation of the error sources, notably the atmospheric propagation and satellite orbital errors inherent in GPS, are the main causes of this accuracy degradation. Several organizations are involved in WADGPS research, and different conceptual approaches have been suggested. The proposed methods all share a common basic assumption: that the error sources which affect the system are broken down into individual error components and are modelled separately. The variance between the different techniques comes from the way in which the different error components are modelled.

Keywords

1. Satellite navigation.2. Differential systems.
Type
Research Article
Information
The Journal of Navigation , Volume 50 , Issue 1 , January 1997 , pp. 109 - 119
Copyright
Copyright © The Royal Institute of Navigation 1997

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Ashkenazi, V., Hill, C. J., Ochieng, W. Y. and Nagle, J. (1993). Wide-area differential GPS: a performance study. Navigation, Journal of the US Institute of Navigation, 40, 3.Google Scholar
Ashkenazi, V., Ochieng, W. Y., Hill, C. J., Moore, T. and Chao, C. H. (1995). An improved wide area differential GPS. Fourth International Conference on Differential Satellite Navigation Systems, April, Bergen, Norway.Google Scholar
Curley, R. A. (1988). The Use of Tl 41OO GTS Receivers and Magnet Software to Determine Height Differences. M.Sc. thesis, University of Nottingham, UK.Google Scholar
Dodson, A. H. (1986). Refraction and propagation delays in space geodesy. International Journal of Remote Sensing, 7, 515.Google Scholar
Klobuchar, J. A. (1977). Ionospheric time delay corrections for advanced satellite ranging systems. Propagation Limitations of Navigation and Positioning Systems, AGARD-CP-209.Google Scholar
Klobuchar, J. A. (1986). Design and characteristics of the GPS ionospheric time delay algorithm for single frequency users. IEEE Plans, Las Vegas, pp. 169–176.Google Scholar
Shardlow, P. J. (1994). Propagation Effects on Precise GPS Heighting. Ph.D. thesis, University Nottingham, UK.Google Scholar