In all capture modes, if you plan to capture global angles, to ensure that the IMU sensor data is stable and to minimize drift, at the start of a day's capturing, you must calibrate the IMU sensors.
To calibrate the sensors:
- Start streaming global angles. (If you're not sure how to do this, see Start Capture.U and choose a capture mode.)
- Wave the sensor in a figure-of-eight for at least 10 seconds.
- Put the sensor on a flat surface.
- Wait until the data has stabilized.
In Real-Time Insight and AR Visualization modes, you can observe that X angle is 0 and the Y angle is 0 (the figure-of-eight provides enough information for the sensor to self-calibrate). However, the Z angle may have a non-zero value, depending on how it is rotated to the magnetic north.
- Rotate the sensor on the flat surface until Z is also 0.
- You can now attach the sensors to your subject and capture data in the required capture mode.