REXDESK: set up GNSS and the IMU

Configure the accelerometer, the gyroscope and the GNSS receiver of your REXGEN, and choose exactly which position data each fix records.

Which loggers this applies to

REXGEN 2 IMU GNSS, REXGEN Air and REXGEN Pro carry an IMU and a GNSS receiver. Dead reckoning is a REXGEN Air feature. So are geofencing and the attitude and IMU items that dead reckoning adds to each fix.

How the logger is mounted matters for motion data. For mounting, see the guide for your logger:

• REXGEN 2 IMU GNSS: recording motion and position
• REXGEN Air: GNSS, dead reckoning and geofencing
• REXGEN Pro: recording CAN FD, LIN, GNSS and IMU

Accelerometer

1. Drop Accel on Channels. In a new project, drag Accel from the Channels group onto the Channels area.
2. Choose the range. Under Range, choose ±2 g, ±4 g, ±8 g or ±16 g. A smaller range resolves small accelerations better. A larger range keeps hard impacts on the scale.

   

3. Set the rate. Enter the Sampling Rate (msec), which is the time between two samples. Select OK.
4. Run the configuration. Select Run, then save and name the project. Logging starts at once.

Gyroscope

1. Drop Gyro on Channels. Drag Gyro onto the Channels area.
2. Choose the range. Under Range, choose ±125, ±250, ±500, ±1000 or ±2000 degrees per second (dps).

   

3. Set the rate and run. Enter the Sampling Rate (msec), select OK, then Run.

Watch: Set up the IMU using REXDESK (0:58)

GNSS settings

Drag GNSS from the Channels group onto the Channels area to open its settings.

Sampling Rate (Hz)

How many position fixes per second the logger records. The range is 1 Hz up to what the receiver supports, which is up to 18 Hz on REXGEN 2 IMU GNSS. For REXGEN Air, see REXGEN Air: technical specifications. For REXGEN Pro, see REXGEN Pro: overview and specifications.

Platform

The kind of movement the receiver expects, which tunes its position filter. Choose the closest. The choices are Portable, Stationary (no movement), Pedestrian, Automotive, Sea, Airborne up to 1g, 2g or 4g, Wrist, Motorbike, Robotic Lawn Mower and Electric Kick Scooter.

Dead reckoning

REXGEN Air only. Combines the IMU with GNSS to keep positioning when satellites drop out. See REXGEN Air: GNSS, dead reckoning and geofencing.

GNSS type

The satellite systems the receiver tracks. Default tracks GPS and GLONASS together. BeiDou, GLONASS and Galileo cannot all be enabled together. In some builds, tick Enable first to show the list. Besides Default, you can choose:

• GPS, Galileo, GLONASS or BeiDou on its own
• GPS + Galileo
• GPS + Galileo + GLONASS
• GPS + Galileo + BeiDou
• GPS + BeiDou
• Galileo + GLONASS
• Galileo + BeiDou
• GLONASS + BeiDou

Items to log

Under Select Items to log, tick what each fix records.

Standard

Latitude, longitude, altitude, speed over ground and course over ground.

Extended

Fix quality, number of satellites, geoid separation and ground distance. Tick both Standard and Extended.

Attitude orientation

The vehicle's pitch, roll and heading (yaw). Dead reckoning models only.

IMU

Acceleration in m/s² and angular rate on the x, y and z axes. Dead reckoning models only.

Geofence

The geofence state, described below. Available once you fill in the geofence fields.

Accuracy

The accuracy figures of each fix. Available once Standard, Extended or Attitude orientation is ticked.

Geofence

On REXGEN Air, the logger can record whether it is inside one circular area. Tick Use Geofence and enter the Latitude and Longitude of the centre and the Radius in metres. Geofencing works only while dead reckoning is active. The recorded value means:

Select OK, then Run, to send the configuration.

Watch: Set up GNSS and its advanced options using REXDESK (2:17)

Next: REXDESK: start and stop logging with triggers.