The role of the Global Positioning System in advanced air combat training ranges

With the Global Positioning System (GPS), tracking to ground level is readily accomplished because the satellites can be observed at all but low elevation angles in all types of terrain. Vertical dilution of precision (VDOP) is poor below about 5000 ft because all multilateration stations are in the same plane as the target aircraft. This forces use of a radar altimeter and terrain model. With GPS, VDOP is nearly constant, yielding constant accuracy throughout the range airspace. With GPS, no permanent surveyed ground sites are required, allowing a portable system for training in a variety of locations. In a GPS tracking system, player-to-player relay can be used to expand the coverage area. Since the data link is not used for multilateration, modern high-capacity data links can be used to handle great numbers of participants. Unmanned electronic warfare (EW) threat emitters have utilized the multilateration tracking system information for pointing. It is concluded that the use of the GPS with modern data links can greatly improve the pointing performance of these threat emitters