Setting Throttle Mid

As mentioned in this link:

at what altitude I have to fly my copter in stabilize mode to log the data’s?
here in that link it is mentioned that “Fly your copter in stabilize mode in a stable hover for at least 30 seconds” but they didn’t mentioned the altitude. Can somebody tell me what is the minimum altitude?

Not sure why you think altitude matters.
Anything above 1 m will do unless it’s a very heavy/big machine.

As they didn’t mentioned any altitude thats why I asked. I just wanted to know the minimum altitude.