Air traffic control and mid-air collisions

Towards a Global Navigation System

“…An analysis of fatal accidents (those in which at least one person was killed) for civil transport aircraft 1946-73, 6 showed that the number of mid-air collisions had not varied statistically significantly throughout the period, averaging at about 2-r per year. Ratcliffe 7 has extended the analysis to the whole period from 1946 to 1989, and shown that the best-fit line corresponds to a decay in the time rate of more than 2 percent per annum; in 1990 the yearly average rate was less than two. He then discusses the role of the Air Traffic Control (ATC) system in holding this rate, despite future traffic growth, by improvements to the ATC system.…”

A Joint data rate - error rate analysis in correlated space-time-wireless channels

“…Examples include: (1) Airborne traffic alert and collision avoidance (TCAS) systems [Williamson and Spencer(1989)] [Kahne and Frolow(1996)] developed for future air navigation systems (FANS) [Trim(1990)] use transponders at airplanes (active targets) for positioning purposes. These systems use the radar principles for range resolution with a range of 10-40 miles [ Ractliffe(1990)] which leads to a limited capacity suitable for those applications. The technique used in TCAS is not feasible for wireless channels, which experience multi-path fading and interference effects, and cover a range of 0.1-1 mile in many applications;…”