Wayne Woldt, J. Alex Thomasson, and John Valasek 2016-05-03 02:00:15
Authors’ note: The official terminology used by the Federal Aviation Administration (FAA) for unmanned aircraft is “unmanned aircraft system” (or UAS), which recognizes that successful flight of an unmanned aircraft relies on an array of systems that include the airframe, fuel and propulsion system, navigation system, on board control system, communication system, ground control station, sensor/payload system, manual control system, and the human pilot. However, there are other terms for this emerging technology, including unmanned air vehicle, remotely piloted aerial vehicle, unmanned aerial system, and remotely piloted aerial system, among others. There are good reasons to employ a given term within the context of a particular application, and we respect this diversity of preferences. For consistency across this three-part series, we have elected to use the terms “unmanned aircraft system” (UAS) and “small unmanned aircraft system” (sUAS). Merely mentioning the words “unmanned aircraft” or “drone” evokes visions of newfangled flying machines that merge aviation with robotics. This “mind’s eye” view is often manifest as an easy-to-fly multi-rotor device capable of vertical takeoff and landing and commonly available at retail outlets. Alternatively, the vision may be of a military fixed-wing aircraft capable of carrying lethal weapons. The invited articles in this special series seek to challenge these “mind’s eye” perspectives on unmanned aircraft and expand the dialogue on their role in agriculture. Part 2 in overview A consensus on standard classification criteria for unmanned aircraft systems (UAS) does not currently exist. The FAA has defined a “small” unmanned aircraft system (sUAS) as a vehicle with a maximum takeoff weight of 55 lb (25 kg). However, there is an emerging continuum of UAS, ranging from the very small (i.e., 1 to 2 lb, or 0.5 to 0.9 kg) to the very large⎯approaching the size of a Cessna or Piper general aviation class piloted aircraft. UAS from various points on this continuum are finding their way into agricultural research and development, and they have the potential to revolutionize breeding research, precision agriculture, and farm management. Two of the following articles in this series describe applications of mid-size and large UAS that are being deployed in their respective research projects. “Precision agriculture: Beyond the domain of small UAS” by Lav Khot and Jianfeng Zhou focuses on an agricultural application of mid-size UAS with a maximum takeoff weight of 207 lb (94 kg), far above the FAA-specified 55 lb (25 kg) threshold for sUAS. The second article, “Large UAS as a practical tool in precision agriculture” by John Nowatzki and Sreekala Bajwa, describes an ambitious, large-scale research project exploring the use of a large UAS for low-altitude long-endurance (LALE) agricultural applications. This particular aircraft has a maximum takeoff weight of 907 lb (412 kg)! Projects involving such aircraft are pushing the bounds of agricultural UAS research and development in new and exciting directions, and the complexity and challenges involved should not be underestimated. The third article in this special series, by Sindhuja Sankaran, describes a research program involving groundbased and remote sensing with rotary-wing sUAS for the purpose of high-throughput phenotyping. Phenotyping is the measurement of a crop’s physical traits (e.g., plant growth rate) to enable selection of preferable crop genetics. Performing this task with sensor platforms like sUAS offers an opportunity to increase the number of genetic lines that can be measured, accelerating breeders’ ability to improve crops. The research program has used sensor platforms along with numerous sensors, including multispectral sensors/cameras, hyperspectral devices, thermal cameras, SONAR, LiDAR, and fluorescence sensors. New regs are on the way To shift gears, or perhaps change altitude, it is well recognized that flight restrictions under current FAA regulations are a challenge for broad-based commercialization and deployment of UAS for agricultural purposes. However, the FAA has indicated that new regulations allowing commercial flight of sUAS in the national airspace system are forthcoming, with projected release in fall of 2016 if not sooner. The FAA introduced these rules through its notice of proposed rule making (NPRM) for commercial sUAS, which was published in the Federal Register. If the FAA continues to move in the directions highlighted in the NPRM, the requirements for commercial sUAS flight will become less restrictive than the current rules, which require operators to earn and maintain, or exhibit knowledge commensurate with, a private pilot license. Salient points from the FAA-issued NPRM for commercial sUAS flight include the following: • The UAS must remain within line of sight of the operator or visual observer. This requirement stems from Section 91.113(b) of the Code of Federal Regulations, stating in part that “vigilance shall be maintained by each person operating an aircraft so as to see and avoid other aircraft.” • Small UAS may not operate over any persons not directly involved in the flight operation. • Flights must be conducted during daylight only, and a visual observer may be used but is not required. • UAS must yield right of way to other aircraft (manned or unmanned), and a “first person view” camera cannot be used to satisfy see-and-avoid requirements. • Maximum altitude of flight operations is 500 ft (152 m) above ground level, and maximum airspeed is 100 mph (87 knots). • Minimum weather visibility is three nautical miles (5.5 km), and operations in Class B, C, D, and E airspace are allowed only with Air Traffic Control permission. • No person may operate or serve as a visual observer for more than one sUAS at a time. • Pilots of sUAS are considered “operators” and would be required to pass an aeronautical knowledge test, be vetted by the Transportation Security Administration, and obtain an operator certificate with an sUAS rating. • Operators would be required to pass a recurring knowledge test every 24 months, be at least 17 years old, conduct a preflight inspection of the sUAS, and report any injury or property damage accidents to the FAA within ten days. • Small UAS must be registered with the FAA. A new “micro-UAS” category is also proposed for UAS that weigh less than 4.4 lb (2 kg). Micro-UAS would be exempt from many of the above requirements. Up and away with ag We are living in dynamic and exciting times for agriculture, with new technologies emerging and disruptive innovations occurring at a high frequency. Agriculture is projected to be the single largest market segment for UAS going forward. The “bird’s eye” view that UAS provide is irresistible to those in agriculture, as it offers so many new opportunities for actionable data. Yet the use of UAS in agriculture is fraught with regulatory and technical challenges, and inevitable growing pains, as research and education pave the way for practical field applications. We hope you will come along for the ride as this series of articles travels across a landscape of UAS applications in agriculture. ASABE member Wayne Woldt, P.E., Associate Professor, Department of Biological Systems Engineering and School of Natural Resources, University of Nebraska-Lincoln, and Director, NU-AIRE Laboratory, Lincoln, Neb., USA, email@example.com. ASABE member J. Alex Thomasson, P.E., Professor, Department of Biological and Agricultural Engineering, Texas A&M University, College Station, USA, firstname.lastname@example.org. ASABE member John Valasek, Professor, Department of Aerospace Engineering, Texas A&M University, and Director, Center for Autonomous Vehicles and Sensor Systems (CANVASS), College Station, USA, email@example.com.
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