Aircraft Tracking, FlightAware, and How You Can Be of Service

摘要

Many readers are aware that many aircraft calculate their location and speed based on GPS, or similar technologies. An aircraft's altitude is measured by a pressure altimeter on board. Pitot tube pressure sensors can also provide speed data as a primary or secondary indication. Not only is this information used by the crew, aircraft with an ADS-B (Automatic Dependent Surveillance-Broadcast) transponder broadcast their identification and three-dimensional position (latitude, longitude, altitude) at 1,090 MHz (or 978 MHz for lower- altitude aircraft in the US, using a different technology), which can be received by a radio within line of sight of the aircraft (a maximum of approximately 250 miles/400 kilometers at cruise altitude).