TABLE OF CONTENTS Landing aircraft in poor visibility imposes the very highest standards of performance for a navigation system. Required to work under extreme weather conditions and at life-critical levels of performance, a Category III (lowest visibility) landing system must meet a vertical position accuracy requirement of 2 ft (95%) with extremely demanding integrity. For each approach, the probability of missed detection of failure cannot exceed 5 10 ?9. This chapter explores the augmentation of GPS with Integrity Beacons a special type of pseudolite to achieve the required navigation performance (RNP) for precision landing of aircraft.
The Integrity Beacon Landing System (IBLS) [1] [3] is illustrated in Fig. 1. It is founded on using GPS augmented with Integrity Beacons compact, low power, ground-based marker beacon "pseudolites" (transmitters used as pseudo-GPs satellites), Integrity Beacons are nominally situated i pairs on either side of the approach path to a runway. The power is set low so that the broadcast signal is measurable only inside of the "bubble" shown in Fig. 1. The bubble radius (determined by the broadcast signal power) is adequate when it is only a few times larger than...
