Drone Wars

Surprisingly, remote-controlled drones have been around for 120 years. Prolific inventor and futurist Nikola Tesla demonstrated the first wireless RC drone in the form of a miniature boat in front of a stunned audience in New York in 1898. Well before its time, onlookers were in disbelief as the boat moved around the tank without an obvious means of control. One even claimed that it must have been powered by a trained monkey hidden inside. Telsa saw the potential of drones and predicted military applications. He tried to sell the idea of RC torpedos which could be used in harbour defense but the military, notoriously conservative, showed no interest. 100 years later, the US military is busy converting its arsenal to remote control to reduce the cost of human lives on the battlefield. Pilots now sit in air-conditioned sheds in Nevada while flying Predator drones in the Middle East. It is believed the term “drone” was coined because of the sound of the pilotless British Fairey ‘Queen’ aircraft of the 1930’s.

Tesla went on to become the archetype for the mad scientist, proposing a form of wireless mind control, an earthquake machine and a death ray capable of bringing “down a fleet of 10,000 enemy airplanes at a distance of 200 miles from a defending nation’s border and will cause armies to drop dead in their tracks”. Robert Watson-Watt was approached by the British Air Ministry about the feasibility of such a death ray. He showed a radio-based version wasn’t possible (although lasers were invented 20 years later) but did show that radio waves could detect the presence of aircraft. The discovery led to radar which played a vital role in preventing a Nazi invasion of the UK in World War II. Tesla saw out his later years broke, feeding pigeons out of a hotel room.

We recently bought a drone, or unmanned aerial vehicle (UAV) as they are better described, to map small areas for geomorphological or glaciological study. The drone has a flying wing design, that was actually conceived by German scientists in the lead up to World War II. The Horton brothers built the jet-powered Ho 229, a revolutionary design that was intended to turn the tide against the fleets of up to 1000 Allied bombers raiding German cities. The aircraft even had early stealth technology to evade British radar. Even if Germany had the resources to produce the aircraft they would have found it devilishly difficult to fly. Without a tail, a flying wing is prone to yaw. Modern descendants of the Ho 229 such as the B-2 bomber use computers to constantly correct their flight. The flying wing design is great for a UAV because it is efficient with a large area for lift for the camera payload while the onboard computer and flight planning software makes the UAV autonomous. Modern lithium-ion batteries ensure a smooth ride for photography. However, landing is interesting because there are no wheels and there are no runways in the field. The drone is designed for uncontrolled landings with replaceable wings.

The maiden flight took place at Woodbury Common, a suitable wide open space with plenty of visibility, with colleagues Steve Palmer and Andrew Nicholas. We took 45 photos over an area of 75,000 m2 which meant with the resolution of our camera we had a ground sampling distance of 2.5 cm. This pixel size allows for even the smallest objects to be identified and allows us to create a digital surface model of about 5 cm. Overall precision of the camera position from onboard GPS was 0.5 m which was very good considering wind on the day.

The advantages of such a precise and accurate means to survey an area are obvious. We can map geomorphology, survey the front of a calving glacier, or photograph a stretch of coast. The applications extend beyond the scientific (and the military). Farmers can plan their crops, engineers can monitor bridges, quarries can manage inventories and mines can improve operation logistics. Tesla’s dream is now a reality.

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