Lou,
When Chunky Paul had a face to face with a Landy we had no problem vectoring the Helicopter in and some us when down the road at various junctions to guide the Ambulance crew in.
With regards the GeoLocation stuff grab me next time you see me I'll be happy to melt your mind/give you some ideas on the subject as I'm in that sorta trade, well Telecoms and emergency call handling from converged networks is always a hot topic.