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Study of GNSS SIS Error Worst User Location Algorithm

Published online by Cambridge University Press:  14 October 2011

Zuo-hu Li*
Affiliation:
(Institute of Surveying and Mapping, Information Engineering University, Zhengzhou, China)
Jin-ming Hao
Affiliation:
(Institute of Surveying and Mapping, Information Engineering University, Zhengzhou, China)
Jian-wen Li
Affiliation:
(Institute of Surveying and Mapping, Information Engineering University, Zhengzhou, China) (Research Centre of GNSS, Wuhan University, Wuhan, China)
Qi-le Zhao
Affiliation:
(Research Centre of GNSS, Wuhan University, Wuhan, China)
Ming-jian Chen
Affiliation:
(Institute of Surveying and Mapping, Information Engineering University, Zhengzhou, China)
*

Abstract

Signal-In-Space Error (SISE) is important for the system integrity of GNSS. Real-time monitoring SISE has been one of the effective solutions used for improving GNSS system-level integrity. As one of the typical solutions, the Galileo integrity concept uses Signal-In-Space Accuracy (SISA) and Signal-In-Space Monitoring Accuracy (SISMA) respectively to transmit the quality of SIS and the integrity alarming information to users. As an important component of the Galileo Integrity Concept, Worst User Location (WUL) is of great importance for the computation of SISA and SISMA. An improved WUL algorithm based on a geometrical model is given in this paper, which needs no iterative search and is simple when compared with the existing models. The WUL accuracy requirement is discussed based on an analysis of the magnitude of the orbit errors and SIS ranging resolution and error. The conclusion is that, considering the metre-level orbital error observed in the orbit determination process, as long as the orientation error of the WUL is less than three degrees, the projection error of SISE can be kept to centimetre levels. This will satisfy the requirements of most users. The algorithm is further optimised to omit the non-linear iterative parts based on the above assumption. The optimisation reduces computation load and enhances the real-time capability. GPS raw measurements are used to validate the correctness and reliability of the algorithms.

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

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References

REFERENCES

Quiles, A., Schlarmann, B. K., Ballereau, A., Hollreiser, M., Durand, J. L., Robert, E. and Schmid, A. (2009). Development and Verification of Galileo Ground Mission Segment (GMS). Proceedings of the 22th International Technical Meeting of the Satellite Division, Savannah, Georgia, USA, 29802989.Google Scholar
Oehler, V., Krueger, J. M., Beck, T., Michael, K., Hans, L. T., Hahn, J. and Daniel, B. (2009). Galileo System Performance Status Report. Proceedings of the 22th International Technical Meeting of the Satellite Division, Savannah, Georgia, USA, 29562966.Google Scholar
Curiel, A. M., Martín, B., Juez, A., Ramírez, M. E., Igual, C., Amarillo, F., Ballereau, A. and Schlarmann, B. (2009). First Integrity Results in Galileo: GIOVE-A Performance Obtained with the Experimental Integrity Process Facility. Proceedings of the 22th International Technical Meeting of the Satellite Division, Savannah, Georgia, USA, 27512763.Google Scholar
Feng, S. J. and Washington, Y. O. (2005). An Efficient Worst User Location Algorithm for the Generation of the Galileo Integrity Flag. Proceedings of the 18th International Technical Meeting of the Satellite Division, Long Beach, California, USA, 23742384.Google Scholar
Guo, Y., Zhao, C. M., Dang, Y. M. and Lu, X. S. (2007). Integrity Monitoring of SISA and Accuracy Algorithm of WUL. Journal of Zhengzhou Institute of Surveying and Mapping, 24(5), 353355. (In Chinese).Google Scholar
Kneissl, F., Stoeber, C. and Eissfeller, B. (2009). Assessment of Combined Integrity Algorithms. Proceedings of the 22th International Technical Meeting of the Satellite Division, Savannah, Georgia, USA, 28042817.Google Scholar
Oehler, V., Francesco, L., Boyero, J. P., Roland, S., Hans, L. T., Hahn, J., Amarillo, F., Crisci, M., Schlarmann, B. and Flamand, J. F. (2004). Galileo Integrity Concept. Proceedings of the 17th International Technical Meeting of the Satellite Division, Long Beach, California, USA, 604615.Google Scholar
Oehler, V., Hans, L. T., Krueger, J., Rang, T., Francesco, L., Boyero, J. P., Hahn, J. and Daniel, B. (2006). Galileo System Design & Performance. Proceedings of the 19th International Technical Meeting of the Satellite Division, Fort Worth, Texas, USA, 492503.Google Scholar
Philippe, P., Christophe, M., Bruno, L. and Mathias, V. (2006). Impact of SISMA Computation Algorithm on User Integrity Performance. Proceedings of the Institute of Navigation 2006 National Technical Meeting, Monterey, California, USA, 709716.Google Scholar
James, B. Y. and Tsui, (2005). Fundamentals of Global Positioning System Receivers, A Software Approach. Wiley-Interscience.Google Scholar
Kaplan, E. (1990). Understanding GPS: Principles and Applications. Artech House Publishers.Google Scholar
Gaetano, G., Manuel, S. G., Francisco, G., Stefano, B., Gianmarco, R., Andreas, H. and Richard, S. (2009). GIOVE-B Navigation Message Performance Anaysis and Signal In Space User Ranging Error (SISRE) Characterization. Proceedings of the 22th International Technical Meeting of the Satellite Division, Savannah, Georgia, USA, 30173024.Google Scholar