Analysis of the Digital Data Communications Link Required for the AutomaticDependent Surveillance System Concept and the Airborne Applications of the Global Positioning System

摘要

Significant changes will be occurring in the next ten years regarding airnavigation and aircraft surveillance. The Global Positioning System, a worldwide satellite-based radionavigation system which provides positioning, navigation, and time information, has emerged as a reliable and incredibly precise means of air navigation which has seen widespread acceptance around the world. With GPS, aircraft can determine their position much more accurately than is possible with ground radar surveillance systems. The current Air Traffic Control system, however, is established in its use of radar surveillance and navigation routes are defined by ground navaids which limit efficiency. The full benefits of GPS navigation cannot be realized without the Automatic Dependent Surveillance system concept. This is a new approach to Air Traffic Control in which every aircraft periodically broadcasts its GPS derived position so that ground controllers and other aircraft in the vicinity can receive and use this information. ADS has the potential to completely replace rotating surveillance radars with fixed omnidirectional antennas for receiving aircraft broadcasts. The key to successfully implementing ADS depends on having a dependable digital data communications link. It is crucial to have an effective mechanism for transmitting aircraft position to air traffic controllers which utilizes equipment that is inexpensive, and yet is effective enough to serve the capacity needs of the system and reliable enough to not compromise safety. Finding the optimal solution to this problem is the biggest issue relating to air traffic control in the near term. (KAR) P. 4-5.