Hostname: page-component-cd9895bd7-gbm5v Total loading time: 0 Render date: 2024-12-26T17:59:44.805Z Has data issue: false hasContentIssue false

Novel Integrity Concept for CAT III Precision Approaches and Taxiing: Extended GBAS (E-GBAS)

Published online by Cambridge University Press:  12 September 2011

Wolfgang Schuster*
Affiliation:
(Centre for Transport Studies, Imperial College London)
Washington Ochieng
Affiliation:
(Centre for Transport Studies, Imperial College London)
*

Abstract

Future air navigation envisages increased use of Global Navigation Satellite Systems (GNSS) together with advanced communications and surveillance technologies to facilitate the required increase in capacity, efficiency and safety without adversely impacting the environment. The full benefit of GNSS is expected from its ability to support en-route to en-route or gate-to-gate air navigation. This presents challenges particularly for the phases of flight with stringent required navigation performance. Significant work has so far been devoted to the phases of flight up to CAT I. However, more work is required for CAT III precision landing (with an accuracy requirement at the metre level) and taxiing (with an accuracy requirement at sub-metre level) and both with very high integrity and continuity requirements. The main limitation in using GBAS for CAT III landings is the potential decorrelation of the measurement errors between the GBAS ground station (GGS) and the user. The threats in this respect are the atmospheric anomalies. Periods of strong solar activity can cause large local spatial and temporal gradients in the delays induced on the GNSS signals by the ionosphere. The local nature of the effects results in significant decorrelation between GGS measurements and the user. Therefore, a reliable ground based ionospheric anomaly monitoring scheme is required to guarantee integrity.

This paper critically reviews state-of-the-art monitors, identifies their limitations and addresses them by proposing a high-performance monitoring scheme for the ionosphere. Preliminary analyses suggest that the proposed scheme has the potential to enable GNSS to meet the navigation requirements for CAT III and taxiing.

Keywords

Type
Research Article
Copyright
Copyright © The Royal Institute of Navigation 2011

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

Datta-Barua, S. et al. (2006). Bounding Higher Order Ionosphere Errors for the Dual Frequency GPS User, ION GNSS.Google Scholar
EUROCAE, (2007). High-Level Performance Requirements for a Global Navigation Satellite System/Ground Based Augmentation System to Support Precision Approach Operations, ED-144, EUROCAE WG28 SG4.Google Scholar
Hofmann-Wellenhof, et al. , (2001). GPS – Theory and Practice (5th ed.), Springer-Verlag.Google Scholar
Konno, H. et al. , (2006a). Ionosphere Monitoring Methodology for Hybrid Dual-Frequency LAAS, ION GNSS, Fort-Worth.Google Scholar
Konno, H. et al. , (2006b). Evaluation of Two Types of Dual-Frequency Differential GPS Techniques under Anomalous Ionosphere Conditions, ION NTM, Monterey.Google Scholar
Liu, X., Tiberius, C., De Jong, K., (2004). Modelling of differential single difference receiver clock bias for precise positioning, GPS Solutions.Google Scholar
RTCA, Minimum Aviation System Performance Standards for the Local Area Augmentation System (LAAS)¸ RTCA-DO245AGoogle Scholar
Schlueter, S., Bauer, T., Schuster, W., (2005). Critical Analysis of Space Based Navigation Technologies Usable for Civil Aviation, ANASTASIA Deliverable D3.1Google Scholar
Skone, S. et al. , (2005). Investigating the Impact of Ionospheric Scintillation Using a GPS Software Receivers¸ ION GNSSGoogle Scholar