AAS (Wide Area Augmentation System) developed by the Federal Aviation Administration to add a Global Positioning System to improve the accuracy, integrity, and availability. Previous AAS is intended to enable the birds rely on GPS for all phases of flight, including precision approach in the coverage area of the airport. AAS systems typically provide better than 1.0 meters and 1.5 meters laterally rather than vertically adjacent in the United States and much of Canada and Alaska. This accuracy is the ability of birds and provideing precision required for safe navigation and for all inflight weather. AAS information integrity is not more than 3 seconds of bad data in the system that will be taken to allow for safe instrument flight rules TOOLS.
Although previously developed for aviation, AAS is not limited sector of space, any GPS receiver capable of receiving signals AAS can benefit from the correction data, makes GPS positioning more accurate. Fact AAS-enabled GPS receiver can even give the right guidance Lane under your car traveling in the (long program to help Lane Ping helpful instructions). For the Wide Area Augmentation System is a rapid in the GPS industry, most new GPS receiver today AAS-enabled. And only if the GPS system conventinal, AAS did not come with additional costs or fees for use. What is needed is that the GPS receiver that allows AAS-so they can receive and Decode data then they can apply the correction position. AAS currently limited services the United States, Canada, Alaska and Hawaii. Although freedom of the AAS, Europe and Asia are their own GPS system additional correction. Europe has a geostationary Euro Display Navigation Service (EGNOS) and Japan is their job Multi-Functional Satellite Augmentation System (SAS).
How System Works AAS
AAS using a network of 25 ground-based Wide-area Reference Stations (WRS) in North America and Hawaii, to measure small differences in the GPS satellite signal in the western world. This real land monitoring survey to collect information on the GPS signal and send information to the three Wide-area Master Station (WMS). WMS production of two different sets of corrections: fast and slow. Fast corrections for errors that are changing rapidly and is the main concern of the instantaneous position of GPS satellites and clock errors. This correction user independent position, which means they can be used directly with a broadcast receiver in the AAS. Correction of the long hours of slow and error ephemeric ionospheric delay estimates and information.
After the correction is produced, a Master Station they will send two pairs of Ground Uplink Station (Gus) correction messages that pass a series of geostationary satellites that broadcast the correction data back to their world. Then AAS-enabled GPS receiver uses this information to make a correction of my original GPS gnial, providing AAS-enabled GPS receiver position is more accurate. S GPS receiver using information broadcast from each GPS satellites to determine their location and the present. Depending on your GPS device, GPS receiver must receive the satellite signals only 3-4 (from the current 31 satellite civilan sign transmiting user) to calculate the position. Apart from the GPS signals, an AAS-enabled GPS receiver can also receive the AAS geostationary satellite signals.
Two different correction message from AAS system (fast and slow) are used by the GPS receiver in a different way. Fast correction of data types including the corrected satellite position and clock data to determine location using GPS when calculating the size. Does the estimated position fix is to get the GPS receiver begins to slow correction increases accuracy. Including ionospheric delay correction Slow data. When the GPS signals travel from the satellite receiver, through the ionosphere. Calculate the location where the receiver signals through the ionosphere and, if the value received from the location of ionospheric delay, it corrects a mistake that creates the ionosphere. Different data and fast, slow data did not need to be updated frequently due to the ionosphere conditions don t change rapidly. While the data can be updated slowly because every minute is important, they are only updated every two minutes, and are considered valid for six minutes.
ASS Deficiency System
(1) AAS system, now available only to the United States and much of Canada and Alaska, but there are plans to expand the system of other continents.
(2) AAS for geostationary satellite broadcasting because they have less than 10 ° above the horizon in the 71.4 ° latitude north. This means that the birds in northern Canada or Alaska might have trouble maintaining a signal lock on AAS.
(3) To calculate the grid point ionospheric's delayed, as it should be between the satellite and center back. The minimum amount of satellites and ground stations to limit the number of points that can be calculated.
(4) AAS method to operate a certified GPS receiver owners.
