Augmented GPS approaches
LPV approaches are based on WAAS satellites which augment the GPS signal. These are known a Satellite Based Augmentation System(SBAS) which sends a correction signal down the the aircraft GPS unit to correct for GPS satellite signal errors for such things as the bending of GPS signals by the atmosphere. This allows the aircraft GPS system to use GPS signals for vertical flight path creation on approach allowing lower minima.
The next stage of development is supposed to be GBAS which is ground augmentation where a ground based system at the airport would send out the appropriate correction signal.
I was under the impression that this was not in use yet but I just read an article that says "Currently, a number of private category 1 GBAS units are installed at test locations in the US and other parts of the world, but only one, in Germany, is understood to have been certified for exclusive use by a specific airline".
Anybody know which airline?