Transmit Power
The term Transmit Power refers to the satellite signal power (signal level) transmitted by GSG during the execution of the currently chosen scenario.
The Transmit Power can be adjusted as described under Adjusting Transmit Power, or during scenario execution (see Setting Transmit Power).
Caution: To learn more about signal level compliance in the United States, see Signal Power Level Considerations. If you live in other countries, check your local emission standards.
- The transmit power is specified in dBm.
- The supported range is: Max. -65 dBm … min. -160 dBm.
- The resolution is: 0.1 dBm.
- Default setting: -125.0 dBm.
Note: The External Attenuation setting decreases the set Transmit Power level.
Note: When the power settings of individual channels are changed during scenario execution (via the > Events menu, or protocol) the power range will be further limited so that the maximum difference between the strongest and the weakest signal is never more than 72 dB.
To access the Transmit Power view, navigate to Options > Transmit Power. This view also allows you to adjust the external attenuation (see Adjusting External Attenuation), and noise (see Adjusting Noise Generation).
Configuring transmit power
The recommended Transmit power setting, assuming relatively short cables and that no external attenuators are used, is -125.0 dBm. If long cables are used, it is recommended that these are simulated by adjusting the external attenuation (see also Adjusting External Attenuation).
The Transmit Power set in the Options menu is assigned to the signal type with the highest power level, and all others are set relative to that.
A common problem is that signals too strong or too weak are used. A signal too strong will typically ‘jam’ the receiver, causing it to erroneously find many shadow signals. It is recommended that you familiarize yourself with the typical signal/noise values for real satellites, and try to obtain similar values when using this unit. When the signal strength is correctly set, the receiver will respond directly and logically to changes in signal power.
The following table shows the offsets when referencing GPS L1 C/A as zero dB offset:
Transmit power offsets
Constellation | Signal | Power offset, dB |
---|---|---|
GPS |
L1 C/A | 0.0 |
L1 P | -3.0 | |
L2 P | -3.0 | |
L2C | 0.0 | |
L5 | +1.5 | |
GLONASS |
L1 | -2.5 |
L2 | -8.5 | |
Galileo |
E1 | +1.5 |
E5a | +3.5 | |
E5b | +3.5 | |
Beidou |
B1 | -4.5 |
B2 | -4.5 | |
QZSS
|
L1 C/A | 0.0 |
L1 SAIF | -2.5 |