Mickjoebill
Came a bit late to this thread. Suggest you contact Prof Albrecht Grimm at IGI GmbH, Kreutztal, Germany. He is the whizz-kid kid on DGPS aircraft positioning systems and loves new problems.
[email protected] or igi-ccns@t-online
IGI pioneered Differential GPS based survey aircraft positioning systems and x, y and z positioning sub 10' is their forte. I've flown hundreds of hours with his toys and never missed a pic yet.
Good luck