Viavi 87339, Operation Manual

Page: 83 / 198

Testing
4 -2
4.1.2 Setup Basic Static Simulation
Perform the following steps for Setup.
STEP PROCEDURE
1. Press Power On/Off Key for a minimum of one second to power up test set.
2. Select Launch Bar tab to display launch bar.
3. Select Setup function key to display Setup Window.
4. Select Simulation tab.
5. Confirm the following settings and change as necessary.
GNSS:
GNSS = GPS
Carrier = L1
SBAS = Off
Simulation = Static
Digital Noise = OFF – when coupling to the receiver antenna. ON – when
connecting directly to the receiver, bypassing the antenna/LNA.
NOTE:
Use of digital noise via receiver antenna, will result in degraded SV Signal to
Noise ratio and may cause receiver to loose track or not obtain a stable fix.
Fading = None
PRN Signal = Fixed
Position Source = User
Simulation Start Time:
Clock = Internal
RF Output:
RF Level = When setting the output level of GPS generated signal, a setting of
115 to -120 dB should be adequate for most receivers. When directly connecting
to a receiver, the nominal gain of the antenna should be taken into consideration
and the output level of the GPSG-1000 adjusted accordingly.
RF Port = COUPLER (if using antenna coupler) or DIRECT (direct connect to GPS
UUT).
Units = Imperial
6. Select Almanac tab on the File page and press Load. Select an almanac from the
list of available items that has been obtained from the internal GPS receiver, or
the U.S. Coast Guard Navigation website that is no more that 30 days old, and
then press the load key.
7. Select I/O tab.
Loss:
Coupler Loss = Figure in dB marked on Antenna Coupler.
Coupler Cable = Figure in dB marked on RF Coax Cable.
Direct Cable = Figure in dB marked on RF Coax Cable.
Input/Output:
Ext Ref Out = OFF
Reference Source - INT
Trigger = Auto
8. Select Simulation Function Key from the Launch Bar.