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Chapter 3 Visual User Interface
Using and Reading the Visual User Interface (the Receiver Status
Screen)
Operating and Programming Guide 3-7
Figure 3-3. Receiver Status Screen Displaying Progress Towards
Steady-State Operation
In the SYNCHRONIZATION area, the >> marker is pointed at the
Locked to GPS line, indicating that the Receiver is locked to GPS and
stabilizing the frequency of its oscillator. This means that the Receiver
has phase-locked its oscillator to the 1 PPS reference signal provided
by GPS, but it is not at its final, or most stable, state. The Receiver is
locked and the front-panel GPS Lock LED is illuminated.
For users without the command interface (PC/Terminal emulator
connected to the Receiver), the illuminated GPS Lock LED is probably
the first indication that after powerup that the Receiver is moving
towards a stable state.
With the command interface and status screen, you can get more
detailed information. For example, you can read the reference outputs
quality indicators in the Reference Outputs area of the status screen.
These are the Time Figure of Merit (TFOM) and Frequency Figure of
Merit (FFOM) indicators. As shown in Figure 3-3, the TFOM is 4 and
the FFOM is 1. These values will eventually decrease towards the
ultimate values that represent steady-state performance. Refer to the
subsection titled ““Reference Outputs” on page 3-13 in this chapter for
more information about TFOM and FFOM.
SYNCHRONIZATION
Receiver Status
---------------------------- ----------------------------
[
Outputs Valid/Reduced Accuracy
]
............................
...............................................
......................................................
ACQUISITION
ELEV MASK
Not Tracking: 1
Locked to GPS: stabilizing frequency
UTC
ANT DLY
MODE
AVG LAT
AVG LON
AVG HGT
HEALTH MONITOR
PRN
Recovery
Holdover
Power-up
SmartClock Mode
Tracking: 6
Self Test: OK Int Pwr: OK Oven Pwr: OK OCXO: OK EFC: OK GPS Rcv: OK
[ OK ]
Time
GPS 1PPS Synchronized to UTC
Position
Reference Outputs
PRN El Az
2
7
19
22
26
C/N
40
38
38
39
36
El
70
35
40
71
19
16 13 258
10 deg
41
1.000 us
+20 ns relative to GPS
[GPS 1PPS Valid]
18:47:07 31 Jan 1996
0 ns
Survey: 5.4% complete
N
W
37:19:34.937
121:59:50.457
+67.94 m (GPS)
>>
Az
301
186
102
60
317
TFOM FFOM
HOLD THR
1PPS TI
Predict 432.0 us/initial 24 hrs
Holdrover Uncertainty
31 3516 41