MagnetometerBiasEstimate (UORB message)
c
uint64 timestamp # time since system start (microseconds)
float32[4] bias_x # estimated X-bias of all the sensors
float32[4] bias_y # estimated Y-bias of all the sensors
float32[4] bias_z # estimated Z-bias of all the sensors
bool[4] valid # true if the estimator has converged
bool[4] stable