SITL Z-Drift in position estimate when drone is doing nothing

[shubang93]

I'm trying to use PX4 SITL using the Typhoon H480 model. All I do is instantiate the simulator using the following commands:

DONT_RUN=1 make px4_sitl gazebo_hexa_x_tilt     
source /opt/ros/melodic/setup.bash     
source Tools/setup_gazebo.bash $(pwd) $(pwd)/build/px4_sitl_default     
export ROS_PACKAGE_PATH=$ROS_PACKAGE_PATH:$(pwd)     
export ROS_PACKAGE_PATH=$ROS_PACKAGE_PATH:$(pwd)/Tools/sitl_gazebo     
roslaunch px4 mavros_posix_sitl.launch vehicle:=typhoon_h480 world:=/workspace/Firmware/Tools/sitl_gazebo/worlds/typhoon_h480.world verbose:=true

Then, I just let it sit there for about 200 seconds. A couple of things happen:

1. There is a sudden increase in noise along Z for IMU measurement
2. Eventually there is a shift in the average value of IMU - Z measurement
   At the second point (circled in the plot), there is a large jump in position estimate of Z. In all of this, the GPS altitude measurement is very stable. What is causing this issue? Am I doing something wrong?
   

The plots from QGroundControl are below:

To reiterate, I'm doing absolutely nothing. Not even arming the vehicle.

[julianoes]

Interesting, thanks for the issue.
FYI @Jaeyoung-Lim @bresch

[Jaeyoung-Lim]

@shubang93 I think this might be related to the oscillations in the vehicle. Could you maybe check if this is reproducible on the iris?

[Jaeyoung-Lim]

Related to #14953

[stale]

This issue has been automatically marked as stale because it has not had recent activity. Thank you for your contributions.

[Jaeyoung-Lim]

Fixed in #16519