I was referring to the mirror diameter. Of course, the area is even much larger. And infrared telescopes on high elevations are certainly better than telescopes

I was referring to the mirror diameter. Of course, the area is even much larger. And infrared telescopes on high elevations are certainly better than telescopes on low ground, still the atmosphere is a big barieer. For that reason the SOFIA telescope was built into a 747, as the airplane gets up to almost 15 kilometers and thus the observation conditions in the infrared range are much better than any ground based observatory. Obviously, an airplane isn't the best platform to mount a telescope. The Webb telescope should be able to provide a way better view into the infrared range than any telescope available so far.