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Abstract

An air traffic surveillance and communication system for air traffic controllers, includes a plurality of ground based first radio transceivers located in specific geographic sectors, respectively, and having a first frequency channel for supporting party-line digital voice and a second frequency channel dedicated to supporting a digital data channel for down-linking dependent surveillance data and for both up-link and down-link data communications. The first and second frequency channels are paired such that each time a frequency change is commanded by the ground both the first and second frequency channels will be automatically tuned to a new air-ground frequency paid. The system also includes a plurality of aircraft based second digital radio transceivers, one located in each aircraft. Each second radio transceiver has corresponding first and second frequency channels and a navigational data source on each aircraft. The navigational data source incorporates triply redundant GPS receivers for producing highly accurate aircraft navigation data selected from aircraft latitude, longitude, altitude, speed, heading and glide data which is coupled to the respective aircraft transceiver for transmission on said second channel to at least one of the plurality of ground based first radio transceivers. Each ground based first radio transceiver has a communication controller for formatting up-link data and separating down-linked surveillance data and disseminating same to air traffic controllers in the sectors of said aircraft. In a preferred embodiment, in a TDMA format with digital radio transceiver operates with a 12.5 kHz spacing, differential QPSK signal modulation is used and each broadcast is by short transmission bursts having a guard band signal preamble and a management/user data field.