The EKF set its heading again once clear of the ground
What ArduPilot says:
- EKF3 IMUN MAGN in-flight yaw alignment complete
- EKF2 IMUN MAGN in-flight yaw alignment complete
Having climbed 2.5 m above the take-off point, clear of steel in the ground, this copy of the EKF (ArduPilot's position and attitude estimator) set its heading and its picture of the magnetic field once more from the compass. Expect it once per flight for each EKF copy, a second or two after lift-off, on copters and on planes in VTOL flight. A small twitch in yaw at that height is this. If “ground mag anomaly” lines come first, the take-off spot is magnetic.
Parameters to look at
| Parameter | What it is |
|---|---|
EK3_MAG_CAL | Magnetometer default fusion mode |
The code that sends it
EKF3 IMUN MAGN in-flight yaw alignment complete
libraries/AP_NavEKF3/AP_NavEKF3_MagFusion.cpp NavEKF3_core::controlMagYawReset() · Open in ArduPilot Copter-4.7.1
EKF2 IMUN MAGN in-flight yaw alignment complete
libraries/AP_NavEKF2/AP_NavEKF2_MagFusion.cpp NavEKF2_core::controlMagYawReset() · Open in ArduPilot Copter-4.7.1