This is done to test the recovery function of the estimator in case
of divergence or sudden extreme hover thrust change.
Also specify seed of random generator
with measurement noise auto-tuning
The purpose of this estimator is to improve land detection and vertical
velocity feedforward
Recovery strategy:
This is required when the setpoint suddenly changes in air or that the
EKF is diverging. A lowpassed test ratio is used as a trigger for the recovery logic
Also, a lowpassed residual is used to estimate the steady-state value
and remove it when estimating the accel noise to avoid increasing the
accel noise when the redisual is caused by an offset.
bresch