Denti:
My aircraft usually tells me its ANP is 0.02NM. Certified down to CAT I autoland/autorollout GLS approaches, in the works to certify it to CAT IIIb status in same which has allready been demonstrated. 60 year old design too, cant be all that bad
RNP "apples and oranges."
I flew 2 CATIII autoland birds. The L-1011 didn't even know what ANP was. The pre-GPS 767 sort of knew....
Wonders have been done with good ILS ground equipment for some 40 years now. The numbers within the last mile or so prior to the runway exceed any sense of RNP and ANP, but it is a different system.
LPV and GLS resemble ILS, not RNP.