Wyatt Emmerich wrote:
My Garmin 530W has something called HFOM and VFOM and the numbers are
usually higher than a couple of feet, which you describe as the practicable
accuracy of a WAAS.

Can you explain this for me?


I can't give you the technical answers. The FAA experts tell me that
the WAAS vertical path on LPV onlykeeps increasing in accuracy from the
PFAF to the threshold, just like an ILS G/S.