Estimated time of arrival

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The estimated time of arrival or ETA (sometimes called ETOA) is a measure of when a ship, vehicle, aircraft, cargo, emergency service[1][2] or computer file is expected to arrive at a certain place. One of the more common uses is in public transportation where the movements of trains, buses, airplanes and the like can be used to generate estimated times of arrival depending on either a static timetable or through measurements on traffic intensity. In this respect, the phrase or its abbreviation is often paired with its complement, "estimated time of departure" or "ETD", to indicate the expected start time of a particular journey.

For example, a certain flight may have a calculated ETA based on the speed by which it has covered the distance traveled so far. The remaining distance is divided by the speed previously measured to roughly estimate the arrival time. This particular method does not take into account any unexpected events (such as new wind directions) which may occur on the way to the flight's destination.

ETA is also used metaphorically in situations where nothing actually moves physically, as in describing the time estimated for a certain task to complete (e.g. work undertaken by an individual; a computation undertaken by a computer program; or a process undertaken by an organization). The associated term is "estimated time of accomplishment", which may be a backronym. For example, Bittorrent clients specify ETA as the expected time remaining for a file to completely download as 1d4h (1 day and 4 hours), 1w2d (1 week and 2 days), etc.

Applications

Accurate and timely estimations of times of arrival are important in several application areas:

Patents

Several patents have been issued for methods or devices for calculating estimated times of arrival, including:

References

  1. Cameron, M.; Brown, A. (May 1995). "Intelligent transportation system Mayday becomes a reality". Aerospace and Electronics (NAECON 1995) 1. IEEE. pp. 340–347.
  2. Propp, Douglas A.; Rosenberg, Craig A. (July 1991). "A comparison of prehospital estimated time of arrival and actual time of arrival to an emergency department". The American Journal of Emergency Medicine 9 (4): 301–303. doi:10.1016/0735-6757(91)90045-L.
  3. Carr, Gregory C.; Erzberger, Heinz; Neuman, Frank (June 2000). "Fast-time study of airline-influenced arrival sequencing and scheduling". Journal of Guidance, Control, and Dynamics 23 (3): 526–531.
  4. Roy, Kaushik; Levy, Benjamin; Tomlin, Claire J. (August 2006). "AIAA Guidance, Navigation, and Control 2006". AIAA. AIAA2006-6324. |chapter= ignored (help)
  5. Lim, A.; Rodrigues, B.; Zhu, Y. (2005). "Airport Gate Scheduling with Time Windows". Artificial Intelligence Review 24 (1): 5–31. doi:10.1007/s10462-004-7190-4.
  6. Xiong, Bo; Luh, Peter B.; Chang, Shi Chung (April 2005). "Group Elevator Scheduling with Advanced Traffic Information for Normal Operations and Coordinated Emergency Evacuation". Robotics and Automation (ICRA 2005). IEEE. pp. 1419–1424.
  7. Rong, Aiying; Hakonen, Henri; Lahdelma, Risto (December 2003). Estimated Time of Arrival (ETA) Based Elevator Group Control Algorithm with More Accurate Estimation. Turku Centre for Computer Scienceo. ISBN 952-12-1289-6. Retrieved July 11, 2012.