SCOTTSBLUFF — In the near future, people can expect to see drones buzzing through the skies carrying out a number of different tasks, Wayne Woldt, director of the Nebraska Unmanned Aircraft Innovation, Research and Education (NU-AIRE) laboratory at the University of Nebraska-Lincoln, told an audience at the Midwest Theater Thursday evening during the Science on Screen event,“Flying Farmhands: The Future of Drone Technology in Agriculture.”
Woldt has been a pilot since 1975 and has ratings for private, glider, hot air balloon and remote, with over 700 hours of total flight time. However, his day-job is as an associate professor and extension specialist at UNL in the School of Natural Resources and the Department of Biological Systems (formerly Agricultural) Engineering.
And like a Venn-diagram of interests, Woldt managed to fuse his love of aviation with his expertise in agriculture.
Around 2012, Congress passed the Federal Aviation Administration (FAA) Modernization and Reform Act of 2012, which opened up unmanned aerial vehicles (drones) for commercial purposes, and for the last six years, Woldt said he has been heavily involved in researching the agricultural applications where drone technologies can be employed.
“All of the market research shows that agriculture is set to be about 70 percent of that unmanned aircraft market,” he said. “With all the work with drones, agriculture is expected to be a big part of that.”
An aerial view offers a strategic advantage, Woldt said. With developments in irrigation have allowed irrigators to apply water selectively to certain areas of a field.
For example, a center pivot irrigation system can apply more water to the top of a hillside or a slope than to the bottom plain.
“One of the challenges, however, is that this is a case where the technology has outpaced the ability to manage it,” he said. “How do we make decisions about applying that water?”
One step is placing soil moisture sensors throughout the field to collect real-time data. However, that can prove to be expensive and a hassle when it comes time to replant.
A solution Woldt and his team have used is deploying unmanned aircraft fitted with specialized cameras and sensors to collect both thermal and multi-spectral data that can later be analyzed to help develop better management plans.
“We can fly over a field and measure a temperature of the field,” Woldt said.
The drones also measure the temperature around them in order to make corrections to engine speed and altitude to maintain consistency when collecting data. The systems do have drawbacks, however. Currently, the FAA limits the height drones can fly to under 400 feet, meaning that the drones will have to capture multiple images of a field in order to get the full picture. Woldt said a 160-acre pivot can yield as much as 22 gigabytes (22,000 megabytes) of images, (a significant amount considering how the “floppy disks” popular about 30 years ago could only hold 2 megabytes worth of data). Once the images are downloaded from a drone, special software is used to “stitch” the images together into a full panorama, which can yield resolutions of a field down to 12 centimeters.
Another project has been the characterization of wetlands. A drone captures data at various points in a three-dimenisonal spiral which can capture the total volume of biomass in an area.
A third application that has been gaining more study has been control of invasive species. A special drone fitted with a tank and sprayer nozzles can carry a payload of herbicides to remote or hard to reach locations and once a pest has been identified, it can be eliminated.
Drones equipped with global positioning satellite (GPS) units can also be used to measure lake water quality. Using special cameras, the drone drops a probe into the water and measures the image quality against the probe at different depths. Because of the ability to track locations by GPS, the results of the test are more consistent and can be repeated with greater accuracy than was previously achievable.
However, drones often have to share the airspace with other low-flying aircraft, creating significant safety concerns, especially for crop pilots. Even so much as striking a bird during take off can provide significant damage to a crop sprayer and put the pilot at risk, concerns that can be magnified when you consider how some commercial drones are made of carbon fiber and most are powered by lithium batteries which can explode when punctured.
In 2015, the Colorado Agricultural Aviation Association (CAAA) conducted a study to determine if low-flying crop pilots could spot drones.
Since the pilots have their eyes focused on the ground rather than the air, the drones proved nearly impossible to spot.
“Dr. Woldt has been working very closely with us to develop a warning beacon to help alert crop pilots to the presence of low-flying drones in the area,” CAAA Executive Director Jessica Freeman said in an interview Tuesday.
Woldt said he has been experimenting with a system that employs an extremely-bright whelen strobe on top of the base-station for an unmanned aircraft to alert pilots to the presence of drones in the area.
“We know that you can’t put a bright enough light on top of a unmanned aircraft,” Woldt said. “It’s been tried, but it’s not possible.”
Another consideration is laws. Under Part 107 of the FAA’s regulations, drone pilots must get a remote pilot certificate from the FAA in order to operate a drone for commercial use. The certificate allows individuals to operate a drone under 55 lbs within a visual-line-of-sight.
After Woldt’s presentation he was joined on stage by Don Masten of AirScout and Tracy O’Neal of Western Nebraska Community College.
Masten said most of the drones he uses are for scouting in correlation with aerial imaging produced by certified aircraft. The drone carries a smart phone which is matched to a tablet. The tablet overlays the image from the aircraft with the live camera feed from the drone. The operator then selects a point in the field using the tablet and the drone automatically flies out to the point, where it hovers over the point and takes pictures of the field. It can then be assigned to take another photo of the field or return to the same location where it was launched from.
“You can get all the information you want, but if you don’t go out and ground-truth it, it’s not worth much,” Masten said. “The drone allows the grower or the operator to go out there when there’s 10 foot tall corn in late August when it’s hot, and he can use the drone instead of wading through the field.”
O’Neal said he has spent a considerable amount of time and money working on his drone, but he envisions using it for fire and search and rescue.
“My long-term goal is to do things locally and try to help the community that way,” he said.
The drones can range anywhere from a modest $600 system, such as the one employed by AirScout, to higher priced rigs like O’Neal's, which can cost upward of $15,000.
“For any of the young people here, this is the future,” Masten said. “It’s a wide-open field that is going to keep getting better and better more and more. If you have an interest in these things get in them now. Get the small ones, the cheap ones, and take your 107 test if you can.
“The future is right here. I guarantee if you get excited about this and get into it, it’s going to be a career.”