SX BLUE GPS iSXblue II+ GNSSTM, Руководство пользователя

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SXblue Series User Manual 93
In Japan, the MTSAT Satellite-based Augmentation System ( MSAS ) has been
deployed by the Japan Civil Aviation Bureau (JCAB). Successful launches of
MTSAT-1R and MTSAT-2 were followed by system integration for MSAS ground
system and MTSATs by transmitting test signal from MTSATs. Purposes of test
signal transmission were to optimize system performance and then to verify that
augmentation information meets safety and performance requirements. Since
those tests had been accomplished successfully, MSAS for aviation use was
commissioned on September 27, 2007.
In India, the Indian Space Research Organisation and Airports Authority of India
have successfully completed the final system acceptance test of the GPS Aided
GEO Augmented Navigation system (
GAGAN ) as announced on November 20,
2007 by Raytheon Company. With completion of the final system acceptance test,
the stage is set for India to embark on the next phase of the program, which will
expand the existing ground network, add redundancy, and produce the certification
analysis and documentation for safety-of-flight commissioning. The launch of their
own communication satellites is scheduled for May 11, 2011. Note that GAGAN is
no longer broadcasting on Inmarsat 4f1.
China has a similar program for a SBAS and the service is named the Chinese
Satellite Navigation Augmentation System (
SNAS ).
The SXblue receiver is capable of receiving correction data from all compatible
SBAS.
Warning – Use of non-commissioned SBAS signals is entirely at your risk
and discretion.
How it Works
A SBAS incorporates a modular architecture, similar to GPS, comprised of a
Ground Segment, Space Segment, and User Segment:
•
The Ground Segment includes reference stations, processing centers, a communication
network, and Navigation Land Earth Stations (NELS)
•
The Space Segment includes geostationary satellites (For example, EGNOS uses Inmarsat
transponders).
•
The user segment consists of the user equipment, such as a SXblue receiver and antenna
A SBAS uses a state-based approach in their software architecture. This means
that a separate correction is made available for each error source rather than the
sum effect of errors on the user equipment’s range measurements. This more
effectively manages the issue of spatial decorrelation than some other techniques,
resulting in a more consistent system performance regardless of geographic
location with respect to reference stations. Specifically, SBAS calculates separate
errors for the following:
•
The ionospheric error