A decade of unmanned aerial systems in irrigated agriculture in the Western U.S.

Authors: CHAVEZ, JOSE - Colorado State University; TORRES-RUA, ALFONSO - Utah State University; WOLDT, WAYNE - University Of Nebraska; Zhang, Huihui; ROBERTSON, CHRISTOPHER - Colorado State University; Marek, Gary; Wang, Dong; HEEREN, DEREK - University Of Nebraska; TAGHVAEIAN, SALEH - Oklahoma State University; NEALE, CHRISTOPHER - University Of Nebraska

Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/8/2020
Publication Date: 8/13/2020
Citation: Chavez, J., Torres-Rua, A.F., Woldt, W.E., Zhang, H., Robertson, C., Marek, G.W., Wang, D., Heeren, D., Taghvaeian, S., Neale, C.M. 2020. A decade of unmanned aerial systems in irrigated agriculture in the Western U.S. Applied Engineering in Agriculture. 36(4):423-436. https://doi.org/10.13031/aea.13941.
DOI: https://doi.org/10.13031/aea.13941

Interpretive Summary: Irrigation is an important requirement for agricultural production in the Western U.S. and small unmanned aerial systems or drones have been used more and more widely to facilitate irrigation and on-farm management decisions. Through a collective effort of researchers from the Western U.S., recent developments in drone-related technologies and methodologies as applied to irrigation management are reviewed in this article. Although it is operational possible to produce maps of actual crop coefficients, actual crop evapotranspiration, and soil water deficits, for irrigation management, the technology and regulations need to evolve further to facilitate a successful wide adoption and application. Improvements and standards are needed in camera spectral ranges, radiometric resolutions and associated calibrations, fuel/power technology for longer missions, better imagery processing software, and higher altitudes flight missions.

Technical Abstract: Several research institutes, laboratories, academic programs, and service companies around the U.S. have been developing programs to utilize small unmanned aerial systems (sUAS) as an instrument to improve the efficiency of in-field water and agronomical management. This article describes a decade of efforts on research and development efforts focused on UAS technologies and methodologies developed for irrigation management, including the evolution of aircraft and sensors in contrast to data from satellites. Federal Aviation Administration (FAA) regulations for UAS operation in agriculture have been synthesized along with proposed modifications to enhance UAS contributions to irrigated agriculture. Although it is feasible to use sUAS technology to produce maps of actual crop coefficients, actual crop evapotranspiration, and soil water deficits, for irrigation management, the technology and regulations need to evolve further to facilitate a successful wide adoption and application. Improvements and standards are needed in terms of cameras’ spectral (bands) ranges, radiometric resolutions and associated calibrations, fuel/power technology for longer missions, better imagery processing software, and easier FAA approval of higher altitudes flight missions among other issues. Furthermore, the sUAS technology would play a larger role in irrigated agriculture when integrating multi-scale data (sUAS, ground-based or proximal, satellite) and soil water sensors is addressed, including the need for advances on processing large amounts of data from multiple and different sources, and integration into scientific irrigation scheduling (SIS) systems for convenience of decision making. Desirable technological innovations, and features of the next generation of UAS platforms, sensors, software, and methods for irrigated agriculture, are discussed.