Viavi 87339, Руководство по эксплуатации

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Testing
4 -9
4.1.6 Sensitivity
GPS receivers usually have two sensitivity figures specified: Acquisition Sensitivity and
Signal Tracking Sensitivity. Acquisition Sensitivity specifies the lowest power level at
which the receiver is able to achieve a position fix. Signal Tracking Sensitivity is the
lowest power level at which a receiver is able to track an individual satellite.
4.1.6.A Signal Tracking Sensitivity
Perform the following steps for signal tracking sensitivity test.
STEP PROCEDURE
1 If connecting GPSG-1000 via Antenna Coupler, perform Antenna Coupler
Installation procedure Section 4.1.1. If directly connecting GPSG-1000 to GPS
receiver under test, proceed to step 2.
2. Perform Setup procedure Section 4.1.2.
3. Select Launch Bar tab to display launch bar. Select SV PRN function key to
display the SV PRN Function Window. The GPS SV’s in view will be displayed in a
table.
4. Turn ON a single high elevation SV by selecting ON/OFF field to ON in the SV line
and then select Apply. Select the close icon to close the Function Window.
Fig. 4-2 SV PRN Single SV Selection
5. Select RF Level and set to -136 dBm.
NOTE:
This is 6 dB above the typical GPS receiver positional tracking sensitivity of
- 142 dBm. If the active antenna is not in circuit, the gain of the antenna should be
subtracted from these figures.