Hey,
is there some professional barometer setup available which determs altitude on centimeter level? i have heard about systems with base station and wireless link. Does anybody got a link for me ? 
thanks in advance
I cannot give you a link to a product but I can tell you that even if you have such a system one big challenge is to have it shielded properly from external influences like air flow. You can have a really good barometer but if the air flow created by moving the drone affects its readings then you lose all that precision.