Bad Compass Health

Hello,
I’m getting more bad compass heath alerts now days. What, exactly, is the algorithm that causes this message to appear? Are there degrees of health? What does the message mean wrt to flight or mission. In general, the error messages and warnings could use a little more fleshing out.
Thanks,
Steven

Steven have you ever read the wiki?

Please see copter.ardupilot.com/wiki/prearm_safety_check/

  1. Verifies that Compass Offsets are not too Large (i.e. sqrt(x^2+y^2+z^2) < 500).

Craig,
No, I did not look at the Copter Wiki since I fly a “Plane”. The “Plane” Wiki does not have this section.
Further the “Copter” Wiki says SEPARATELY:

  1. Verifies that the [color=#00BF40]Compass is Healthy[/color] and communicating properly.
  2. Verifies that Compass Offsets are not too Large (i.e. sqrt(x^2+y^2+z^2) < 500).
    5.Verifies that the Compass Live or Log based calibration has been performed or that “COMPASS_LEARN” is on.
  3. Verifies Adequate Compass Magnetic Field Strength: (APM1/APM2 about 330, PX4/Pixhawk about 530)

My “Bad Compass Health” occurs in flight. On the ground it is fine. My offsets are all <100. I have Compass Learn enabled. I will check my tlogs for field strength. [color=#FF00BF]Edit: checked the logs for field strength and it’s always above 500.[/color]

So, since compass health is a separate line above, is it something other than a combination of 4,5 and 6?
And I still think a list of what warnings mean would be valuable.
Thanks,
Steven