Orolia GSG-5 Series, User Manual With Scpi Manual, Page: 199 / 392

5.4 NMEA Logging
GSG offers the possibility to log a scenario’s execution in NMEA data. Every second a “snap-
shot” of the user and satellites’ status is taken and recorded in the form of 3 standard
NMEA sentence types.
RMC sentence describes essential GPS position, velocity and time
GGA sentence describes essential fix data, providing 3D location and accuracy data.
Height of geoid above WGS84 ellipsoid is being approximated according to EGM96
geoid model and fix quality defaults to GPS fix (SPS).
GSV sentences (1 to 4 depending upon the number of SV’s) describe the actual
satellites in view.
NOTE : In GSV sentences, an SV’s SNR estimate is given based on the following:
When noise is ON:
SNR = CNo - NF
When noise is OFF:
SNR = min (56, Channel Power + BN - NF - Lc)
Where NF is (“Noise Figure” of receiver) = 1,
Lc (cable loss) = 1,
and BN (background noise level) = 174 dB
You can access this "snapshot" by using the SCPI command
SOURce:SCENario:LOG?
,
which can be queried at a maximum rate of 1Hz. See the GSG SCPI Guide ( "Command
Reference" on page 227 ) for more details.
It is also possible to use StudioView to log NMEA data: Tools > Data Recorder .
5.5 Execution Log
During everyday operation, your GSG unit will maintain a log, which is kept in the file
obser-
vations/executionlog.txt
. In this log file, the unit stores information about the scen-
arios run, and possible errors that may have occurred, which can be helpful with
troubleshooting.
To view the Execution log:
On the GSG front panel display, navigate to Options > Manage files > obser-
vations : executionlog.txt . Press the Arrow right key to highlight the View option,
and press enter to display the log.
In GSG StudioView , use the File Manager .
5.4 NMEA Logging
User Manual GSG-5/6 Series Rev. 27 183