NavCom SF-2040 Rev.E - Manual (Page 48)

SF-2040 User Guide - Rev. E
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 Processing Centers located
geographically distant from each other and running
continuously, each receiving all of the reference site
inputs and each with redundant communication links to
the uplink sites (LES). The Land Earth Stations 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 Redondo Beach, California and
Moline, Illinois. Through these integrity monitors the
network is continuously checked for overall
DGPS
positioning accuracy, L-Band signal strength, data
integrity and other essential operational parameters.
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