Ground-based GPS tracking

The animalplanet aired a sequence last night using Tilly the Golden
Eagle to search for a hiker in a rugged mountainous area ... I think
the diameter was 5 miles. Rather then carrying a real-time camera,
Tilly had a GPS unit that was sending "real-time" lat/lon/altitude info
that was being mapped on the host's laptop ... similar to watching a
trace on SeeYou. The show said the unit was military-grade GPS unit
(quick response and high accuracy) ... don't know if it is true. The
animalplanet.com site didn't have any additional details. Anybody know
what hardware/software supported this ... or how close we are in
deploying (easily, reliably, cheaply) something like this to support
spectator involvement at contests.

gracias'

KK