Copter Landing with Rangefinder - Do I need Terrain Following?

ArduCopter Copter 3.6
1

Can I use a rangefinder to get accurate altitude data for landing a copter?

I can only find rangefinder references in the documentation associated with Terrain Following.

I do not think I need Terrain Following, just altitude control like the barometer would have done.

It appears from the documentation that if you set RNGFND_MAX_CM to a value within the rangefinder’s capability it will switch from the barometer to the rangefinder below that altitude.

Is this true?

Thanks,

Paul