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Several three_d_sensor_calibration messages


Total Posts: 3

Joined 2018-07-30



I'm parsing a .fit file. So far it goes quite well and I managed to stabilize using the Gyro and align using the Accelerometer.
But there is something that is unclear to me.
When having the following set of messages (a simple example I made up to make the question clear):

1. three_d_sensor_calibration - timestamp=1, sensor_type= compass
2. magnetometer_data - timestamp=10, timestamp_ms=0
3. magnetometer_data - timestamp=11, timestamp_ms=0
4. magnetometer_data - timestamp=12, timestamp_ms=500
5. magnetometer_data - timestamp=13, timestamp_ms=0
6. three_d_sensor_calibration - timestamp=12, sensor_type= compass
7. magnetometer_data - timestamp=10, timestamp_ms=500
8. magnetometer_data - timestamp=10, timestamp_ms=500

(As you can see there 2 calibration messages - 1 and 6, and 6 data message 2-5, 7-8)
Which calibration info should be used to calibrate each message?
messages 2-3 come after calibration-message 1, and before 6's timestamp.
message 4-5 come after 1, but with a timestamp that is after 6's timestamp.
messages 7-8 come after 6, and with a timestamp that is after 6's timestamp.

If you can also refer me to a documentation that clarifies this issue.

I'm using A Garmin camera. But I think this issue happens with other products as well.