INNOVATION September-October 2015

f ea t ures

The intake of the Dasque Hydroelectric Project, as photographed by an unmanned aerial vehicle

and landing area about 30 x 150 m in size, are better served by the more efficient fixed-wing aircraft. On the other hand, rotary wings provide greater maneuverability and flexibility with payloads. New products that blend the two styles into a flexible and efficient airframe are being developed. Aircraft type, flying weight, and battery capac- ity determine a UAV’s working time. Operators can expect flight times for rotary-wing UAVs to range from 10 to 15 minutes, and for fixed-wing craft to last about 45 minutes. With many UAVs capable of airspeeds of about 50 km/h, they can complete a substantial amount of work in a single flight. While many applications require only a well-composed aerial oblique photograph that may be collected in less than one minute, other operations require careful planning to capture all of the required data in mul- tiple flights. Complex or multiple-flight operations may require multiple battery packs, as over-discharg- ing batteries can result in a UAV failing mid-flight, the aircraft landing badly and being damaged or destroyed, and collected data being jeopardized. In many applications, operators seek to photo- graph or video terrain or structures. In these cases, the UAV’s airframe serves as a platform for a camera payload. The desired product quality determines which camera sensor is selected for use. In turn, the mass of the sensor determines the airframe and required battery capacity. Many UAVs—including

expensive ones—are designed to carry an action sports camera. These cameras suit many needs, but their small sensor size and low-resolution capabili- ties present drawbacks for more advanced photo- graph processing. Large, heavy, high-quality cameras require the upscaling of many of the UAV system’s components, which increases complexity and cost. New operators may wish to consider starting with basic equipment. As they become familiar with the capabilities and limitations of their UAV systems and with piloting, they will gain a better sense of the scope of their operational needs and the possibilities their existing equipment presents, and what upgrades would best meet their project requirements. Piloting Piloting a UAV is a fairly simple task, because of the technology of on-board flight controllers. Of the more than 40 training flights I have supervised, only a few have returned with a ‘hard’ landing. The skill required for piloting rests in being able to position and smoothly move the aircraft to produce quality images. Practicing in a safe envi- ronment is the best way to become a proficient and safe pilot. Beyond the auto-leveling and position-holding features of most consumer UAVs, some flight controllers allow for semi-autonomous flights. Operators program a flight path into a laptop or mobile device, then send the information to the

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