Just to offer up how we do it in a fairly major european shorthaul carrier:
We practice Cat 2/3 Autolands on a Cat 1 Promulgated ILS to Cat 1 minimums.
The only big differences between a Cat 1 and Cat 3 ILS are:
A guaranteed
instant back up should the transmitter fail at a critical moment.
and
As many have already said, the course structure is guaranteed because of the critical areas being free of vehicles and a/c on the ground close to the localiser and g/p aerials.
That means the decision to land/go around is made at 190 feet, but the a/p can stay in all the way to the roll out at 60 knots.
Obviously we check ALN, FLR and RET and all that good stuff as you would in a proper Cat 2/3 a/land.
Makes sense really - if any deviations occur between 190' and 60 knots you just disconnect and take over manually.
It's only a little Fokker so it's not as sophisticated or involved as a big transport like an L1011.
