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Aviation Sri Lanka 


Future trend

Satellites provide a better system of area navigation than ground-based radio stations. In the 1980s the U.S. Department of Defense developed a highly accurate satellite-based navigation system known as the Global Positioning System, or GPS. GPS and other satellite navigation systems provide highly accurate positioning information to anyone using an appropriate receiver.

GPS-type systems are so accurate that the FAA and its international counterpart, the International Civil Aviation Organization (ICAO), have agreed that satellite navigation will become the standard for international aviation navigation. Satellite navigation provides adequate accuracy for in-flight navigation, but will need to be improved if it is to guide aircraft during the more complex landing procedure. Two systems have been developed and are planned for installation by the FAA. One system, called the Wide Area Augmentation System (WAAS), uses a satellite transmitter to send accuracy corrections to all aircraft operating over the continental United States. The other, the Local Area Augmentation System (LAAS), will be installed at airports to provide guidance information that will allow automated aircraft landings in any type of weather.

One type of instrument navigation that does not rely on radio or satellite transmissions is inertial guidance. Inertial guidance uses mechanical or laser gyroscopes to determine precisely an aircraft's direction of flight. When an inertial guidance system has been programmed correctly, it can provide direction to any point in the world. Although inertial guidance is fairly costly, its biggest advantage is that it is a self-contained system, independent of either ground or space-based transmitters.