Ensuring the GNSS Onboard Integrity Function Under Adverse Conditions - Feasibility and Flight Test Results

Carsten Butzmiihlen

Abstract:	Due to the undisputed high level of accuracy and its marginal needs of terrestrial infrastructure, satellite navigation is in principle the most suitable candidate for positioning tasks under adverse environments where conventional radio navigation aids fail. Nevertheless, all four Required Navigation Performance (RNP) parameters, i.e. apart from accuracy these are availability, continuity of service and integrity, have to be complied with prior the considered navigation system can be certified Considering this background, the Institute of Flight Guidance and Control participated recently in a flight test programm in Lugano, Switzerland, which the Swiss Federal Office of Aviation (FOCA) supported. Flight test were performed under highly dynamic and adverse environments with the additional use of low- cost inertial information. The landscape in which these test were realized leads to the risk of extensive shadowing of the space vehicles, thus increasing the probability that the GNSS is not available in order to compute a position solution. Additionally, the mountains provide a reflecting surface of the radiofrequency signals. Hence, multipath reception has to be dealt with as well. The paper describes an approach to ensure the onboard integrity function of the GNSS using additional information that is available onboard the aircraft (Aircraft Autonomous Integrity Monitoring AAIM) and compares the performance of the AAIM strategy with the properties of several RAIM strategies (Receiver Autonomous Integrity Monitoring). Even with multi-error scenarios failure detection and (with a few restrictions) exclusion is possible with AAIM. Applying the RAIM strategies to multi-error scenarios, the limitation to one error source can give rise to a false identification of a space vehicle.
Published in:	Proceedings of the 1996 National Technical Meeting of The Institute of Navigation January 22 - 24, 1996 Loews Santa Monica Hotel Santa Monica, CA
Pages:	757 - 764
Cite this article:	Butzmiihlen, Carsten, "Ensuring the GNSS Onboard Integrity Function Under Adverse Conditions - Feasibility and Flight Test Results," Proceedings of the 1996 National Technical Meeting of The Institute of Navigation, Santa Monica, CA, January 1996, pp. 757-764.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In