wide-area augmentation system

Wide-Area Augmentation System

[¦wīd ¦er·ē·ə ȯg·mən′tā·shən ‚sis·təm] (navigation) A satellite-based augmentation system developed by the Federal Aviation Administration in the United States. Abbreviated WAAS.

wide-area augmentation system (WAAS)

The WAAS is a satellite navigation system consisting of the equipment and software that augment the GPS (global positioning system) Standard Positioning Service (SPS). The WAAS provides enhanced integrity, accuracy, availability, and continuity over and above the GPS and the SPS. The differential correction function provides the improved accuracy required for precision approaches. This augmentation of the GPS system will permit its use as a primary means of navigation for en route travel, non-precision approaches, and CAT I approach capability at some airports.
WAAS is based on a network of approximately 35 ground reference stations located in the Continental United States. Each of these reference receivers is precisely surveyed, enabling each to determine any error in the GPS signal being received at the station. The error is then fed to the master station computer which calculates correction algorithms and assess the integrity of the entire GPS system. The data is then up linked to a communication satellite in a geostationary orbit. This communication satellite forwards the correction signal to the aircraft's GPS receiver. The aircraft receiver then makes necessary adjustments to provide improved positioning accuracy. The communication satellites also act as GPS navigation satellites, thus adding to the number of satellites in the GPS constellation.

单词	wide-area augmentation system
释义	wide-area augmentation system Wide-Area Augmentation System [¦wīd ¦er·ē·ə ȯg·mən′tā·shən ‚sis·təm] (navigation) A satellite-based augmentation system developed by the Federal Aviation Administration in the United States. Abbreviated WAAS. wide-area augmentation system (WAAS) The WAAS is a satellite navigation system consisting of the equipment and software that augment the GPS (global positioning system) Standard Positioning Service (SPS). The WAAS provides enhanced integrity, accuracy, availability, and continuity over and above the GPS and the SPS. The differential correction function provides the improved accuracy required for precision approaches. This augmentation of the GPS system will permit its use as a primary means of navigation for en route travel, non-precision approaches, and CAT I approach capability at some airports. WAAS is based on a network of approximately 35 ground reference stations located in the Continental United States. Each of these reference receivers is precisely surveyed, enabling each to determine any error in the GPS signal being received at the station. The error is then fed to the master station computer which calculates correction algorithms and assess the integrity of the entire GPS system. The data is then up linked to a communication satellite in a geostationary orbit. This communication satellite forwards the correction signal to the aircraft's GPS receiver. The aircraft receiver then makes necessary adjustments to provide improved positioning accuracy. The communication satellites also act as GPS navigation satellites, thus adding to the number of satellites in the GPS constellation.
随便看	polymerase chain reaction of short tandem repeat sequences polymerase chain reaction product polymerase chain reaction restriction fragment length polymorphism polymerase chain reactions polymerase chain reaction-sequence specific oligonucleotide probe polymerase chain reaction with sequence-specific primer polymerase chain reaction–single strand conformation polymorphism polymerase chain reacton polymerase (dna directed), alpha polymerase (dna directed), alpha 1 polymerase (dna directed), alpha 1, catalytic subunit polymerase (dna directed), beta polymerase (dna directed), delta 1, catalytic subunit 125kda polymerase (dna directed), delta 2, regulatory subunit 50kda polymerase (dna directed), delta 3 polymerase (dna-directed), delta 3, accessory subunit polymerase (dna-directed), delta 4, otthump00000236818 polymerase (dna directed), gamma polymerase, dna, eta polymerase, dna or rna polymerase gamma polymerase ii, rna, subunit a polymerase initiation complex polymerase (rna) ii (dna directed) polypeptide a 220kda polymerases