NavCom SF-2110 Rev.C - Manual (Page 78)

SF-2110 User Guide – Rev. C
All the reference stations are built with duplicate
receivers, processors and communication interfaces,
which switch automatically or in response to a remote
control signal from the processing centers. The data
links from the reference stations use the Internet as
the primary data link and are backed up by dedicated
communications lines, but in fact the network is
sufficiently dense that the reference stations
effectively act as back up for each other. If one or
several fail, the net effect on the correction accuracy
is not impaired.
There are two continuously running processing
centers, each receiving all of the reference site inputs
and each with redundant communications links to the
uplink LES. The LESs are equipped with two
complete and continuously operating sets of uplink
equipment arbitrated by an automatic fail over switch.
Finally, a comprehensive team of support engineers
maintains round the clock monitoring and control of
the system.
The network is a fully automated self-monitoring
system. To ensure overall system integrity, an
independent integrity monitor receiver, similar to a
standard StarFire user receiver, is installed at every
reference station to monitor service quality. Data from
these integrity monitors is sent to the two
independent processing hubs in Torrance, California
and Moline, Illinois. Through these integrity monitors
the network is continuously checked for overall SBAS
positioning accuracy, L-Band signal strength, data
integrity and other essential operational parameters.
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