Integrity Concept for Image-Based Automated Landing Systems

Christian Tonhäuser, Alexander Schwithal, Stephan Wolkow, Maik Angermann, Peter Hecker

Abstract:	The amount of automatic approach and landing systems is in recent years supplemented by area navigation and computer vision-based systems. The approach for image-aided final approach and landing is object of research in the project C2Land led by the Institute of Flight Guidance of the Technische Universität Braunschweig. Object of study is an integrated GNSS/INS geolocation system supported by video cameras and a long range laser scanner to aircraft-autonomously enhance geolocation. The additional sensors replace the classical navigation infrastructure on ground in order to be independent of international airport structures. This paper focuses on an innovative integrity concept of the navigation system. Based on standardized Receiver Autonomous Integrity Monitoring (RAIM) and Aircraft Autonomous Integrity Monitoring (AAIM) algorithms a new system integration is introduced which therein embed optical sensors. Key feature in Integrity Monitoring is fulfilled by Protection Level calculation, Fault Detection and Exclusion. Each of these integrity components is investigated for compliance with the optical sensor aided navigation system. Common AAIM concepts are designed for a specific set of aircraft sensors, for example inertial/barometric system corrected by tight coupling of GPS/INS measurements as proposed by [1]. With the introduced optical sensor set the calculation of Integrity Risk and therefore integrity probabilities is reevaluated. For a complete coverage of Fault Detection (FD) situations every FD probability is investigated. Based on the principle introduced by [1] and [2] a new Protection Level calculation and Fault Detection is introduced, which merges common AAIM techniques with statistics about reliability of optical correction data. Furthermore image processing quality and sensor constellation geometry are taken into account. With the Integrity Monitoring concept introduced in this paper the basis of a fully integrated GNSS/INS/optical navigation system is designed. Flight tests deliver proof of concept.
Published in:	Proceedings of the ION 2015 Pacific PNT Meeting April 20 - 23, 2015 Marriott Waikiki Beach Resort & Spa Honolulu, Hawaii
Pages:	733 - 747
Cite this article:	Tonhäuser, Christian, Schwithal, Alexander, Wolkow, Stephan, Angermann, Maik, Hecker, Peter, "Integrity Concept for Image-Based Automated Landing Systems," Proceedings of the ION 2015 Pacific PNT Meeting, Honolulu, Hawaii, April 2015, pp. 733-747.
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