Roj - "At the point where you reach the DH, 97Ft RA, you will be 100Ft above the landing runway. (There is obviously a 3ft difference in the height of the ground at that point to the end of the runway, ARTE)
I hope that helps"
Not really - slightly irrelevant? It disregards the wording quoted by 66. I repeat, with emphasis:
A Category 2 decision height must be identified by reference to radio altitude and must not be less than
100ft arte or the OCH
What do you reckon the OCH is?