title: Vision-Aided RAIM: A New Method for GPS Integrity Monitoring in Approach and Landing Phase.
abstract: In the 1980s, Global Positioning System (GPS) receiver autonomous integrity monitoring (RAIM) was proposed to provide the integrity of a navigation system by checking the consistency of GPS measurements. However, during the approach and landing phase of a flight path, where there is often low GPS visibility conditions, the performance of the existing RAIM method may not meet the stringent aviation requirements for availability and integrity due to insufficient observations. To solve this problem, a new RAIM method, named vision-aided RAIM (VA-RAIM), is proposed for GPS integrity monitoring in the approach and landing phase. By introducing landmarks as pseudo-satellites, the VA-RAIM enriches the navigation observations to improve the performance of RAIM. In the method, a computer vision system photographs and matches these landmarks to obtain additional measurements for navigation. Nevertheless, the challenging issue is that such additional measurements may suffer from vision errors. To ensure the reliability of the vision measurements, a GPS-based calibration algorithm is presented to reduce the time-invariant part of the vision errors. Then, the calibrated vision measurements are integrated with the GPS observations for integrity monitoring. Simulation results show that the VA-RAIM outperforms the conventional RAIM with a higher level of availability and fault detection rate.
authors.affiliation: School of Electronic and Information Engineering, Beihang University, Beijing 100191, China. fuli@ee.buaa.edu.cn.
authors.forename: Li
authors.initials: L
authors.lastname: Fu
authors.affiliation: School of Electronic and Information Engineering, Beihang University, Beijing 100191, China. buaazhangjun@vip.sina.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhang
authors.affiliation: School of Electronic and Information Engineering, Beihang University, Beijing 100191, China. lee_ruin@ee.buaa.edu.cn.
authors.forename: Rui
authors.initials: R
authors.lastname: Li
authors.affiliation: School of Electronic and Information Engineering, Beihang University, Beijing 100191, China. xbcao@buaa.edu.cn.
authors.forename: Xianbin
authors.initials: X
authors.lastname: Cao
authors.affiliation: School of Civil and Environmental Engineering, UNSW Australia, Sydney NSW 2052, Australia. jinling.wang@unsw.edu.au.
authors.forename: Jinling
authors.initials: J
authors.lastname: Wang
mesh_terms: D000465:Algorithms; D001359:Aviation / Q000379:methods; D003198:Computer Simulation; D040362:Geographic Information Systems
keywords: GPS; RAIM; VA-RAIM; approach and landing phase; aviation navigation; computer  vision