JJ wrote:

LAAS (Local Area Augmentation System) was to provide CAT 2 and 3 ILS
capability at major airports by fine tuning GPS and up loading
correction signals to aircraft. FAA has canceled the program. Looks like
the ground based ILS systems once slated for removal by 2010 are here to
stay.

There is a variation on this theme, however. Boeing has spent no small
amount of money developing and testing its own LAAS system at Mose Lake,
Washington. It does awesome things with appropriate equipment Boeings,
which is mainly a few 737-900s at the present time. The aircraft can fly RF
legs (radius to fix legs) so even the turns are positive course guidance
along a precisely defined arc segment. I suspect the Boeing model could
become a future private system for advanced RNP instrument approaches at
difficult airports,