Discrete Address Beacon, Navigation and Landing System

Abstract

A system is described which relates to the FAA's developmental Discrete Address Beacon System (DABS). However, the DABNLS is an integrated system and would provide not only air traffic control surveillance data and a two-way data link (including ground derived traffic advisories) of DABS, but it would also provide precision area navigation and versatile landing guidance with a full Category IIIc capability. Further, its transmissions include three-dimensional position data on all aircraft, thus supplying simple straight forward means for a cockpit traffic environment display on an effective and economic collision avoidance system with horizontal as well as vertical escape maneuver capabilities. For the enroute structure the DABNLS would utilize a single pair of L-band frequencies for the discretely addressed up-link interrogations and down-link replies. The ground facility would make precise azimuth and range measurements on the bi-phase coded reply pulses, and, with the reported altitude data, digitally process the data to obtain the aircraft's latitude/longitude and other parameters. This data is broadcast on the following interrogation for navigation by the addressed aircraft, and for collision avoidance purposes by all other aircraft. The ground facility uses the data for ATC purposes. Multiple channels would be used in the terminal areas, each with the addition of elevation facilities for landing guidance. Substantial economies would be accrued with both ground and airborne equipment, as well as added operational capabilities, with implementation of DABNLS. Even a single channel airborne transponder would provide ATC surveillance, area navigation, and collision avoidance for the smallest aircraft throughout the country, and make practical for the first time the longstanding FAA desire of surveillance of all aircraft.