Lidar downward facing for height measure

I have a lidar forward facing for object avoidance. I want to place a second one downward facing but just to measure height accurately. How can i set this up without engaging the object avoidance?

When you set it looking down, it automatically becomes the height sensor and displays as sonar range , it’s not part of the RADAR screen anymore.

Yes but i dont want it to follow terrain though. How can i disable that?

You leave Baro as altitude sensor
As written in the Terrain Following wiki
Do not set the EK2_ALT_SOURCE or EK3_ALT_SOURCE parameters. These parameters should be left at “0” (barometer).

Do not set the EK2_RNG_USE_HGT or EK3_RNG_USE_HGT parameters. These parameters should be left at “-1”.

thanks. so as i have the ifrst lidar as oject avoidance now i should use the RNGFND2_ parameter i guess