The Aircraft Situation Display to Industry (or ASDI)
data stream
In connection-oriented communication, a data stream is the transmission of a sequence of digitally encoded coherent signals to convey information. Typically, the transmitted symbols are grouped into a series of packets.
Data streaming has b ...
is a service made available through the
U.S. Department of Transportation's Volpe Transportation Center. In 1991, data on the location of aircraft was made available by the Federal Aviation Administration to the airline industry. The ASDI stream consists of data elements which show the position and flight plans of all aircraft in U.S. and optionally, UK airspace. Elements include the location, altitude, airspeed, destination, estimated time of arrival and tail number or designated identifier of air carrier and general aviation aircraft operating on IFR flight plans within U.S. airspace. Aircraft owners and operators may request limited dissemination of such data, after which a particular aircraft is deemed "ASDI-blocked", however weak encryption of
ACARS
In aviation, ACARS (; an acronym for Aircraft Communications Addressing and Reporting System) is a digital datalink system for transmission of short messages between aircraft and ground stations via airband radio or satellite. The protocol was des ...
data means that in practice aircraft operational data can still be captured and decoded using simple equipment.
A preceding system, the
Semi-Automatic Ground Environment
The Semi-Automatic Ground Environment (SAGE) was a system of large computers and associated networking equipment that coordinated data from many radar sites and processed it to produce a single unified image of the airspace over a wide area. SA ...
(SAGE) air defense network, utilized flight plans matched to radar returns, continuously and automatically, to aid in identifying aircraft. Computer programs recorded the number of times an aircraft deviated from its assigned course and notified appropriate personnel each time a deviation occurred. IBM and MITRE Corporation were the developers of the SAGE system.
Much of MITRE's subsequent air traffic control collaboration with the FAA was based on SAGE system developments.
References
External links
Information site for the ASDI data stream(hosted by the
FAA)
Aviation in the United States
Air traffic control
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