Precise Low Altitude Control

I need to stay at precise low altitude(above ground level) with copter guided mode
I tried it with relative location and global location by setting ground global altitude(msl) as reference before takeoff
i also have lidar sensor which i was using but now i have payload that does pendulum swing and sometimes it affects measurements. I tried using a verification algorithm which compares new value to old values while calculating range with difference of old values
i ll go with lidar + algorithm for now but i want to learn and use other methods to stay at precise agl

Did you try using surface tracking:

It should have a lot of improvements in the 4.1.0-beta8 release.

Thanks for the reply. Earlier today i read these Terrain Following docs but couldn’t understand how to use it at guided mode.