ARP
REN
I had the same thought, similar to the Runway end lights. But I can't from memory recall if it is the same for other ILS equiped RAAF/Joint aerodromes. (TVL, WLM)
Maybe one of our RAAF ATC guys can give this one a go, that is if any are still here in Aust and not in Bagdad.
ARP = Aircraft Rediness Platform.
I don't know the answer, but don't be too quick to discount the terrain idea. A quick look at the threshold shows that the Runway slopes up to the west (29) and the terrain to the east slopes down to the threshold. Plus the light poles on AmyJohnsotone Ave may not provide the required obst free gradiant for ILS. Just a thought.