WAAS in Australia

[duncan_g]

Actually the location and number of stations has little to do with airports - the station density is required to generate a sufficiently detailed map of the ionosphere so that local corrections can be calculated by the SBAS receiver. The more stations you have, then the more ionospheric measurements you have, which means you can have a higher resolution map of the ionosphere.

So the number of stations required to cover the whole of Australia would be roughly the same as the U.S.

edit: I should clarify by saying that I think a level of performance can be achieved with a smaller number of stations, but the vertical integrity required for APV approaches might not be achieved with sufficient availability...

edit: replace WAAS with SBAS.