Record and Replay

LabSat 4 Record and Replay variants use an internal SSD to record GNSS data.

You can also connect to and use an external USB storage device to record the data. 

Antenna

The placement and setup of the GNSS antenna will depend on the use case. However, if you are using a vehicle to record the scenario file, it is important that the antenna is placed in the ideal location on the vehicle. 

You can read more about antenna placement on a vehicle here.

LabSat 4 has 3 RF channels. This gives you the ability to record 1, 2 or 3 frequency bands.

You can configure the recording of the desired constellations, including frequency, bandwidth and quantization, in the Constellation menu on the front panel display or in the Frequency Setup menu in the LabSat 4 Web Server. You can select up to 3 of the desired constellation groups. 

When you have configured the constellations, you can exit the menu and press the REC button to begin recording. The unit will create a new file each time it starts recording. The file name will be File_001 where the number will be one higher than the highest already saved on the media. 

Battery Life

To maximise battery life during recording, LabSat 4 has a power-save mode enabled by default. You can change this setting in the Setup Menu. The power-save mode recognises when the unit is running from battery power and will dim the display backlight and power down the internal GNSS monitor after 1 minute with no user activity. 

If you are recording from passive antennas, such as the Maxtenna M1516HCT-SMA GPS/GLONASS antenna, enabling the power-save mode will also provide the highest possible sensitivity by ensuring that unused modules in LabSat 4 are switched off.

Recording Example

This is an example of how to record a file to the internal SSD on LabSat 4.

Record Screen

The Record Screen will display the number of satellites, the allocated file name, the recording duration, and the CAN and RS232 logs being recorded (if enabled). The flashing square next to a signal type indicates that the signal is being recorded. When a recording is complete, the File Selection Screen will open with the recorded file in the list of available files.

Additional Info

During recording, if the SSD becomes full, the recording will stop automatically. 

LabSat 4 contains an onboard GNSS receiver that gives you the ability to monitor the RF signals during record or replay. If you press the OK button while the unit is recording, it will switch the display to show available satellite levels for the different constellations. In this display mode, you can use the UP/DOWN buttons to toggle between the different constellations. Press the OK button in this display mode to open the file status. Press the OK button again to return to the record status display mode.

LabSat 4 Record & Replay variants use an internal SSD to replay GNSS data.

You can also connect to and use an external USB storage device or a Network Attached Storage (NAS) device to replay the data. 

Connections

The RF OUT connector on the rear panel of LabSat 4 is a 50 Ω output that can be connected directly to the antenna input of the GNSS receiver under test. The RF OUT connector on your LabSat 4 is DC blocked internally to make it safe to connect almost any device to this port.

Replaying Example

Example of how to replay a scenario file from the SSD.

Replay Screen

The Replay Screen will display the number of satellites, the file name, the replay duration, the progress through the length of the recording file and any applied signal attenuation. When the replay has finished, the File Selection Screen will open.

Additional Info

LabSat 4 contains an onboard GNSS receiver that gives you the ability to monitor the RF signals during record or replay. If you press the OK button while the unit is replaying, it will switch the display to show available satellite levels for the different constellations. In this display mode, you can use the UP/DOWN buttons to toggle between the different constellations. Press the OK button in this display mode to open the file status. Press the OK button again to return to the replay status display mode.

Replay Behaviour

Pressing Play

When you press the Play/Pause button to start replaying a file, the unit will display the status "Playing" while the file is being prepared. The file will start playing, with the replay settings configured in the Play Options Menu, as soon as it is ready.

Looped

If you have selected to loop the file during the replay, you will see the Loop symbol displayed on the right-hand side, above the progress bar, when the file starts replaying. The file will continue to play until you press the Play/Pause button again.

Looped with Pause

	If you select to loop the file during replay, but with an added pause before the file loops, LabSat 4 units will display a Loop with Pause symbol on the right-hand side, above the progress bar, when the file starts replaying.
	When the file has finished replaying, LabSat 4 will display a message stating that the replay has been paused and a countdown with the set pause time. When the countdown reaches 0, the file will restart from the beginning.

Play From and Play For

If you have set a time you want to start the replay From in the Play Options Settings,  LabSat 4 will display an arrow at the beginning of the progress bar to indicate that the setting has been applied.  If you have set a time you want the replay to Play For in the Play Options Settings,  LabSat 4 will display an arrow at the end of the progress bar to indicate that the setting has been applied.