Agricultural drones collect important data

The big picture Agricultural drones survey property and collect data to improve quality and increase yields

BY NICOLE ZEMA

Asky-high perspective of farm operations offers more than just a pretty picture.

As drone functionality soars and units become more affordable, Virginia agriculturists are exploring their use in improving crop quality, increasing yields and surveying livestock and property. Light- and distance-measuring technologies affixed to drones can accurately determine crop status, and even predict disease symptom onset, resulting in greater profit for producers.

Whether the devices are used for checking on sheep, looking for wildlife damage, counting crops or measuring plant volume to calculate yields, researchers want to make drones accessible to Virginia farmers.

Sky’s the limit for technological potential

What will save tobacco growers the most money and make their operations more profitable? Researchers at Virginia Tech’s Southern Piedmont Agricultural Resource and Extension Center in Nottoway County are developing systems that should answer that question.

Hyperspectral imaging devices may have potential to detect slight indicators of crop quality, often invisible to the naked eye. In 2018, while Austin Hayes was studying for his master’s degree at the center, they conducted an experiment in a grower’s black-shank infested tobacco field.

“We were trying to see if we could separate healthy plants from plants that appeared healthy but soon became symptomatic,” Hayes said. “We took several readings over a period of two weeks. By doing that, we were able to look through the lens of time, to tell

PHOTOS COURTESY OF VIRGINIA TECH

A bird’s-eye view of Virginia Tech’s Kentland Farm and Sheep Center as seen with drones, which are used in the college’s Agricultural Technology program.

which plants were pre-symptomatic, and when.”

Comparing the readings, researchers found statistical differences in data between healthy plants and seemingly strong plants that would later become symptomatic for the soil-borne disease. Equipment pinpoints unhealthy crops

“We used a hyperspectral radiometer, which takes a point measurement rather than an entire image,” Hayes explained. “Hyperspectral sensors and cameras allow us to measure beyond the range of visible light to get a unique spectral signature for an object.”

A spectral signature can ultimately illuminate those minor differences. That information could be empowering to tobacco growers, who can follow up with a precise management decision, like fungicide or early harvest.

But the typical farmer may not have the expertise or computational resources to interpret layers of data that will describe the field, or $70,000 to purchase a hyperspectral radiometer.

“We’re trying to take first steps into developing a system so a grower can fly a drone over their own field and interpret the information and act on it,” Hayes said.

To make the device more affordable, research is directed toward identifying the specific bands of the spectrum needed to detect specific diseases and other plant stresses, said Dr. David Reed, tobacco agronomist at the center.

Graduate research assistant Caleb Hinkle is working on multiple projects to study how nicotine levels vary among different tobacco varieties, the ability of drone technology to determine tobacco yields, and the implementation of drones as a scouting tool in farming operations. Specialized cameras affixed to drones measures leaf area, volume and plant size, and categorizes tobacco plants as small, medium or large. These data may be used to highlight areas in the field that are underperforming and may require management attention.

“The camera works directly with a specialized sensor that measures ambient light, cloud cover and atmospheric densities of gasses that can change light that we can’t see,” Hinkle said. “You can go out and see what the issue is in that specific spot, so you’re not scouting an entire 100-acre field.”

Reed’s team has been contacted by a company interested in implementing drone-assisted precision agriculture on a countrywide basis.

“They could predict what the yield

Caleb Hinkle, a graduate research assistant at Virginia Tech, demonstrates drone use in a tobacco field in Nottoway County.

Farmers attend a drone instruction class at Virginia Tech.

PHOTO BY NICOLE ZEMA

Caleb Hinkle and Austin Hayes, Virginia Tech graduate research assistants, with a drone used in tobacco research.

Agricultural educator Dan Swafford, right, demonstrates drone technology with a student attending a drone conference at Virginia Tech.

Lidar, or Light Detection and Ranging, is used to develop 3D models of farmland that discern the precise terrain, allowing farmers to make informed management decisions.

Thermal images of cows can show the advantage of silvopasture systems in reducing heat stress in livestock. will be for an entire country in Africa,” Reed said. “We are collecting data to utilize in our research, certainly, but we want to extend that to other growers in the future.” Students, farmers benefit from drone use

The next generation of aerial agriculturalists are aiming high at Kentland Farm, a tract of land owned by Virginia Tech’s College Farm Operation in Montgomery County. The two-year Agricultural Technology Program in the College of Agriculture and Life Sciences prepares students to enter the industry or be an asset on their own farms. The airfield at Kentland and the college’s Drone Park facility are environments to explore unmanned systems operations.

Use of a quadcopter and a fixedwing drone are part of the curriculum, affixed with a Normalized Difference Vegetation Index device, which measures light reflection at certain frequencies to determine plant health.

“We’ll fly over any number of the fields and correlate that data with what we might be actually seeing in the field,” said Wesley Gwaltney, program instructor.

He said graduate Brady Louk won the $16,500 fixed-wing drone in a trade show raffle and donated it to the program.

“It’s not a toy drone to take pictures while you’re hiking,” Gwaltney said. “It takes off vertically, flies and returns to its take-off point and lands. There’s no joystick. A tablet operates the flight, processes the imagery and it is userfriendly.”

For Dan Swafford, a part-time research associate who works closely with the program, access to agricultural drones is personal. He knows a farmer with limited physical mobility who needs to check on his sheep. A $500 drone does the footwork from 75 feet or less.

“It’s a check-on tool,” Swafford said, explaining that drone-assisted flock monitors can look for new lambs or sick sheep. “And the sheep don’t care about the drones flying overhead; they’re used to it.”

Flying drones on the farm during the winter

Drone use is limited by weather conditions, and winter weather can affect flight times and drone reliability.

Cold temperatures can cause the charge life of a drone battery to drain quickly. The following are tips to help reduce the effects of cold weather on drone batteries. • Always check batteries before flying. • Charge batteries to 100% within 24 hours of flying. • Always put warm batteries into the drone. • If possible, keep the drone in a warm vehicle until just before flying.

Besides the standard pre-flight checks, additional precautions should be taken to prevent damage to drones when flying in the cold and snow. • Avoid getting the drone wet from rain or snow. • Dry props before takeoff to avoid getting moisture into the motors. • Use a landing pad to keep the drone out of the snow during takeoffs and landings.

The following procedures will allow the drone to have its maximum flight time during cold conditions. • Use manual takeoff, and allow the drone to warm up on the ground at least 30 seconds before taking off. • Allow the drone to hover for a while after takeoff. • Use full throttle during flight operations to help extend the battery charge. • Fly at a lower altitude to accomplish the work to be done. • Check battery charge level constantly while flying.

Information courtesy of Dan Swafford and Morgan Paulette, Virginia Tech Cooperative Extension Service, and Dr. Marshall Swafford, Eastern New Mexico University BY ADAM CULLER

Drones are increasing in popularity among farmers, but if they’re being used for commercial purposes, it’s important that operators follow Federal Aviation Administration regulations before flying.

The FAA defines commercial use of unmanned aerial vehicles or drones as “the operation of unmanned or model aircraft for non-hobby and nonrecreational purposes.” Commercial operators are required to obtain a Remote Pilot Certificate and follow the FAA’s small unmanned aircraft, or Part 107, regulations.

According to the FAA, there are three main steps to obtaining this certification:

Understanding the rules

To obtain a Remote Pilot Certificate, individuals must first become familiar with Part 107 rules. Under these regulations, commercial drone operators must: • Operate a drone that weighs less than 55 pounds, and fly under 400 feet above ground level. • Keep unmanned aerial vehicles within the commanding pilot’s line of sight or that of a visual observer. • Fly during daylight hours or civil twilight hours—30 minutes before official sunrise to 30 minutes after official sunset—with appropriate anti-collision lighting. • Fly at or below 100 mph. • Abstain from flying over groups of people. • Be aware of FAA airspace restrictions. • Yield the right of way to any manned aircraft. • Remain at least 400 feet away from lateral boundaries of critical infrastructure, which includes airports, military bases, federal prisons and power plants.

A comprehensive list of Part 107 regulations can be found at bit.ly/2RYGZPV. Additional waivers may be requested for operations not covered under Part 107. Acing the test

To become an FAA-certified pilot, individuals must first pass an aeronautical knowledge test.

Test registrants must be: • At least 16 years of age • Able to read, write, speak and understand English • In a physical and mental condition to safely fly an unmanned aerial vehicle.

Before registering for the test, individuals must obtain an FAA Tracking Number by creating an Integrated Airman Certification and Rating Application at iacra.faa.gov.

After obtaining an FAA Tracking Number, registrants must schedule an appointment to take the $160 knowledge test at an FAA-approved testing center.

Once the test has been passed, complete FAA Form 8710-13 for a Remote Pilot Certificate. The certificate is valid for two years, and certificate holders are required to pass a recurrent knowledge test every two years. Registering your drone

Once certified, pilots must register their drones with the FAA. Registration costs $5 and is valid for three years. Individuals must have the make and model of their drone when registering.

Visit dronezone.faa.gov to create an account and register your drone. Once registered, mark your drone with your registration number in case it’s lost or stolen.

Note: All drone operators are required to register their aircraft with the FAA if it weighs more than 55 pounds, even if it is being used for recreation.

For more information regarding drone certification, visit faa.gov/ uas/commercial_operators/ or knowbeforeyoufly.org/commercial/.