# EKF behaiour is not clear Increasing magnetometer innovations during "static" test

**URL:** <https://discuss.px4.io/t/ekf-behaiour-is-not-clear-increasing-magnetometer-innovations-during-static-test/28960>\
**Category:** PX4 Autopilot\
**Created:** [September 8, 2022, 9:16am UTC](https://discuss.px4.io/t/ekf-behaiour-is-not-clear-increasing-magnetometer-innovations-during-static-test/28960 "2022-09-08T09:16:55Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![cheralex](https://discuss.px4.io/user_avatar/discuss.px4.io/cheralex/32/11468_2.png) [@cheralex](https://discuss.px4.io/u/cheralex)\
**Post date:** [September 8, 2022, 9:16am UTC](https://discuss.px4.io/t/ekf-behaiour-is-not-clear-increasing-magnetometer-innovations-during-static-test/28960/1 "2022-09-08T09:16:55Z")

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Hi, I’m messing with 3-axis magnetometer tests on 1.12 firmware (1.3 working the same way).  
Copter placed on a vertical string and freely rotates over vertical axis. I’m spining it around and observe how the heading behave. According to the code, the vertical rotations is a condition where 3-axis magnetometer became observable, hence the experiment seams to be valid.  
So after some runs, **mag\_test\_ratio** hits its limits and the heading became not valid.

 ![image](https://discuss.px4.io/uploads/default/original/2X/0/0841ecf23d1c927669b585c7e1066b96d9979347.png)  
[https://logs.px4.io/plot\_app?log=52070fb6-8e95-4b98-be65-50a52f0296ef](https://logs.px4.io/plot_app?log=52070fb6-8e95-4b98-be65-50a52f0296ef)  
The vehicle is a standard DJI 450 frame,  
CubeBlack  
External compass replaced to be inline with internal. ROTATION = NONE  
The question is: Is it an expected behaviour of EKF or I’m doing something wrong.