Large vs. Small UAS: Researchers Explore Which Will Cut it for Farming

A Hermes 450 unmanned aircraft system (UAS) recently took flight to help North Dakota State University (NDSU) with an agricultural research project that tests out large versus small UAS for crop and livestock production.

The project will use the Hermes 450 and small multi-rotor and fixed-wing UAS to collect imagery from a four- by 40-mile corridor in east-central North Dakota every two weeks during the 2016 crop-growing season. The Hermes 450 will gather images from altitudes of 3,000, 5,000 and 8,000 feet, and the small UAS will fly at 400 feet or below.

North Dakota Agricultural Experiment Station scientists and NDSU Extension Service specialists are collaborating with the Hillsboro Airport Authority, local Traill and Steele County producers, and Fort Worth, Texas-based Elbit Systems of America on the project.

Elbit is a subsidiary of Elbit Systems Ltd., an Israeli company that provided the Hermes 450, a UAS with a 35-foot wingspan. According to NDSU, that’s similar to the wingspan of a single-engine manned aircraft.

The UAS, which was flown in sections to the U.S. from Israel, then trucked to North Dakota and is being flown out of the Hillsboro Municipal Airport, where it will be based for the duration of the project.

“Small UAS are ideal for scouting crops and livestock and can be used effectively to capture imagery for precision management decisions, such as variable-rate in-season fertilization, weed identification, livestock inventory and identifying sick animals,” says John Nowatzki, the extension service’s agricultural machine systems specialist and the principal investigator on the project.

“But small UAS are relatively limited by flight time and cannot easily capture imagery of thousands of acres on the same day,” he adds. “Large UAS will be needed to collect high-spatial and temporal-resolution imagery over entire regions in a timely manner.”

One of the benefits of using UAS for agricultural purposes is saving time, but if a producer has to drive a small UAS from field to field, then it really isn’t much of a time saver, according to Sreekala Bajwa, chair of NDSU’s agricultural and biosystems engineering department and a co-investigator on the project.

The UAS will collect data on stand counts in corn, sunflowers and sugar beets; the effectiveness of nitrogen applied to corn and wheat; iron-chlorosis deficiency in soybeans; and yield predictions for corn, soybeans, wheat, sugar beets and sunflowers. The researchers plan to test whether UAS also can benefit livestock producers, such as by inventorying cattle in pastures.

The intent is to compare the data collected from the air at various altitudes through satellite imagery, in-field observations and on-the-ground sensors, detailed soil analyses, and harvest yield information. The researchers also plan to assess the costs associated with collecting UAS imagery.

“This research is the first of its kind in the nation,” Bajwa says.

A Research ND grant from the North Dakota Department of Commerce is partly funding the project. Trajectory information from the UAS flights will be shared with the Federal Aviation Administration (FAA), which recently approved the Hermes 450’s flight as part of the Northern Plains UAS Test Site, one of the six FAA-selected UAS test sites.

Because the FAA requires the UAS to be flown within the operator’s line of sight, the North Dakota wing of the Civil Air Patrol will fly a chase plane with a visual observer, who will be in constant radio communication with the ground-based Hermes 450 operators, Nowatzki says.