Quadcopters being able to find their way around without human intervention or GPS is ideal. DARPA is already working on the idea. DARPA’s FLA program is all about enabling unmanned quadcopters to fly autonomously through cluttered buildings at fast speeds up to 45 mph. They have smart algorithms to self-navigate.
Most people don’t realize how dependent current UAVs are on either a remote pilot, GPS, or both. Small, low-cost unmanned aircraft rely heavily on teleoperators and GPS not only for knowing the vehicle’s position precisely, but also for correcting errors in the estimated altitude and velocity of the air vehicle, without which the vehicle wouldn’t know for very long if it’s flying straight and level or in a steep turn. In FLA, the aircraft has to figure all of that out on its own with sufficient accuracy to avoid obstacles and complete its mission.
explained JC Ledé, the DARPA FLA program manager. More info is available here.