While air traffic control systems track, guide and monitor thousands of planes and helicopters every day, one group of sky flyers remains unmonitored: drones.
In recent years, small unmanned aerial vehicles (UAVs), such as commercial quadcopters and hobby drones, have become less expensive and easier to fly — adding traffic to airspace that’s already congested. Drones are also more adaptable for terrorist or military purposes, and because they are currently flying unmonitored, U.S. forces want to be able to quickly detect and identify UAVs, especially in urban areas …
Live Science | Sept. 21, 2016
http://www.livescience.com/56177-darpa-aerial-dragnet-drone-monitoring.html
