Bad GPS Pos

I am trying to track down what causes the ‘Bad GPS Pos’ error on APM Planner, but cannot find any documentation explicitly stating what that feedback is tied to (Number of satellites? HDOP (or other DOP) value?)

Would anybody be able to shed some light on what produces that error? Or the piece of documentation that does detail it?


(Apologies if this is redundant, erroneously posted it in the MP forum, should have been here from the start)

it’s sent by the autopilot. Look here for more information on GPS HDOP (Horizontal Degree of Precision) which relates to the BAD GPS POS message.