Comment Re:Altitude? (Score 1) 223
Actually, if the drone is equipped with both ADS-B transmit and receive, and within range of a ground station, they will receive TIS-B data for the local area, which is essentially the same radar that traffic control sees. So as long as these drones are in ground station range, they will see your friends.
http://en.wikipedia.org/wiki/Automatic_dependent_surveillance-broadcast
http://www.faa.gov/nextgen/flashMap/index.cfm