I'm a bit constrained as to how much detail I can put out but to answer some of the questions... IP68? - yes, it really does need to be that, though not, as I said, when operating. Power? - yes, battery would be fine as the operating period is relatively short. No more than 1hr will cover it. Moving? - yes, the reception end will be moving, although within a constrained area. Something like a 30 degree beamwidth from the transmitter would keep the receivers covered. Worst case would be to go old-schooll and have someone pointing the antenna at the reception target area.