NavCom SF-3050 Rev.A - Manual (Page 147)

SF-3050 User Guide – Rev A
C-145
StarFire in
measureme
receivers and the user r
frequency receivers at b
and the user
processing
accuracy of the StarFire system possible.
Creating the corrections is just the first part. From our
two processing centers, the differential corrections
are then sent to the Land Earth Station (LES) for
uplink to L-Band communications satellites. The
uplink sites for the network are equipped with
NavCom-built modulation equipment, which
interfaces to the satellite system transmitter and
uplinks the correction data stream to the satellite that
broadcasts it over the coverage area. Each L-Band
satellite covers more than a third of the earth.
Users equipped with a StarFire precision GPS
receiver actually have two receivers in a single
package, a GPS receiver and an L-Band
communications receiver, both designed by NavCom
for this system. The GPS receiver tracks all the
satellites in view and makes pseudorange
measurements to the GPS satellites. Simultaneously,
the L-Band receiver receives the correction
messages broadcast via the L-Band satellite. When
the corrections are applied to the GPS
measurements, a position measurement of
unprecedented real time accuracy is produced.
Reliability
The entire system meets or exceeds a target
availability of 99.99%. To achieve this, every part of
the infra
.
ll the reference stations are built with duplicate
receivers, processors and communication interfaces,
which switch automatically or in response to a remote
which dual-frequency ionospheric
nts are available at both the reference
eceivers. It is the use of dual-
oth the reference stations
equipment together with the advanced
algorithms, which makes the exceptional
structure has a built-in back-up system
A