Autonomous Integrity Monitoring for GPS-Based Precision Landing Using Ground-Based Integrity Beacon Pseudolites

Boris Pervan, Clark Cohen, David Lawrence, H. Stewart Cobb, J. David Powell, and Bradford Parkinson

Abstract:	The Integrity Beacon Landing System (IBLS), developed and tested at Stanford University, is a high integrity solution to GPS-based Category III precision landing. IBLS is a kinematic GPS system which incorporates ground-based Integrity Beacon pseudolites placed under the approach path. The large geometry change that occurs during pseudolite overtlight ensures observability for direct cycle ambiguity estimation. Once cycle ambiguities have been initialized, position fixes accurate to the centimeter level are possible. The real-time accuracy performance of IBLS has already been demonstrated through flight tests in a Piper Dakota. The large number of redundant measurements resulting from Integrity Beacon overtlight and the great precision of carrier phase measurements provide the leverage for receiver autonomous integrity monitoring @AIM). Extremely tight detection thresholds may be set without incurring high false alarm rates (preserving high continuity). The measurement residual statistic can be used to detect a wide specuum of fault scenarios, including cycle slips, intentional tampering or spoofing, and spacecraft ephemeris errors. The overall level of IBLS system integrity as well as accuracy, continuity, and availability is quantitatively assessed through analysis, simulation, and flight test. Preliminary results show that the Required Navigation Performance (RNP) specification for Category III integrity of one undetected failure in one billion approaches is achievable using RAIM with Integrity Beacons. Flight tests were performed in a Piper Dakota with purposely induced navigation system failures to demonstrate the effectiveness of real-time autonomous integrity monitoring with Integrity Beacons. The results of these experiments are discussed.
Published in:	Proceedings of the 7th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 1994) September 20 - 23, 1994 Salt Palace Convention Center Salt Lake City, UT
Pages:	609 - 618
Cite this article:	Pervan, Boris, Cohen, Clark, Lawrence, David, Cobb, H. Stewart, Powell, J. David, Parkinson, Bradford, "Autonomous Integrity Monitoring for GPS-Based Precision Landing Using Ground-Based Integrity Beacon Pseudolites," Proceedings of the 7th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 1994), Salt Lake City, UT, September 1994, pp. 609-618.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In