mapping precision issue

[greymfm]

We are using this ROS package in order to get a high-precision realtime LiDAR-odometry estimation for a Livox MID-360 LiDAR. We verify the precision with a robot that exactly follows lines via GPS RTK (1cm error) that are apart 18cm.

After each robot turn, the mapping is moving 10cm up and down in X and Y axis (we can see that the walls are moving up and down). As a result, the odometry result does the same. The robot path lines in the LiDAR odometry are not 18cm apart from each other.

Question: Any ideas how we could improve the mapping precision?