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Drones evolve into a new tool for ag
Loss of pilots over hostile territory fueled the birth of the drone in 1918. Nearly a century later, the mention of the word evokes a negative connotation.
“I think the first thing you imagine when you hear the word drone is this image of a predator operating in Afghanistan with an assault weapon or missile strapped underneath,” says Rory Paul, of Volt Aerial Robotics.
Yet, these devices, which Paul refers to as unmanned aerial systems (UAS), have the potential to be more than just spies in the sky. A passionate advocate for the use of this technology in agriculture, Paul has been working to change that image from foe to friend.
“UAS are something more intelligent than just a target drone that is shot down by antiaircraft artillery,” he notes.
Though he’s been working to introduce the concept to agriculture since 2006, it’s only recently that the tides have turned.
“It is an area that has been ignored, but there’s a change in the focus that has happened in the last few months,” says Paul. “The big defense players are slowly turning their eyes toward the potential these devices hold for ag applications.”
The greatest possibilities, he believes, are in aerial imagery and data acquisition. He also thinks size won’t matter when reaping the benefits. “These systems will be operated by small and large farmers to acquire data when they want it,” he says.
Agent for change
Despite the potential value UAS bring to agriculture, there are still challenges to navigate. Their use falls under the jurisdiction of the Federal Aviation Administration (FAA). It is in the process of developing rules and a plan for commercial use of UAS in national airspace by 2015, which is currently strictly prohibited.
As both a full-scale, instrument-rated private pilot and a model airplane enthusiast, Roger Brining has been flying model remote-controlled (RC) aircraft for recreational use under the rules and safety guidelines of the Academy of Model Aeronautics (AMA) since the 1970s.
“Model aircraft have successfully and safely coexisted with full-scale planes for years,” he says. “The FAA has worked with the AMA for decades to ensure that safety is maintained. The catch is that all of these guidelines and safety programs specifically exclude any commercial use of RC aircraft. Once we get into a company charging a farmer to take aerial imagery, this becomes a commercial use.”
The one area the FAA believes will see the largest near-term growth is in small UAS (sUAS, which are under 20 pounds). By the end of 2013, it is expected to release a proposed rule governing the use of sUAS. It could take a few more years, however, before a final rule is implemented because of the comment and review process that follows.
“There is no question there will be FAA regulations on what can and cannot be done with sUAS,” says Brining, who farms in Great Bend, Kansas. “This is a must for their safe coexistence with manned aircraft.”
Universities also see this tool as an ally for many in the industry.
“UAS can reduce equipment wear and tear as well as labor and fuel costs to get highly precise data you wouldn’t necessarily be able to gather going through the field at ground level,” says Kevin Price, professor of agronomy and geography at Kansas State University.
For over a year, Price, along with Deon van der Merwe, an associate professor at Kansas State’s college of veterinary medicine, have been collaborating to explore how unmanned technology can play a role in ag missions.
They have uncovered a wide range of uses with the help of two units: a RiteWing Zephyr II and a DJI S800 Spreading Wings hexacopter.
For example, they’re working with professors who do crop breeding with literally thousands of plant crosses. Seeds are planted in patches, and larger fields are filled with thousands of patches.
“Professors walk the field looking at each patch and its phenology, which is the way the plant looks – its height and shape,” Price says. This information is then used to estimate yields.
“Every patch is harvested, and seeds of the different varieties are weighed,” he continues. “It can take up to 1,500 hours of labor to get one phenotype, which is a bottleneck for moving the genetic breeding program along.”
To speed up the process, he looked to a spectroradiometer, which measures the energy coming off the plants in thousands of wavelengths.
“With two wavelengths – red and near-infrared – we can explain over 80% of the variability in yields on these thousands of phenotypes. If we can take those two wavelengths and build them into a camera, we can fly a field, take an image, and project the yield on every plot in minutes. We can ignore the bad plots and not have to collect that data. It’s going to save millions of dollars in research time.”
Beyond the crop, he can see UAS counting cattle, checking for water in the pond, or determining if blue-green algae that can kill livestock is present.
Other jobs that once took hours, if not days, are reduced to minutes. “We mapped an area of about 640 acres in 18 minutes,” he says.
The camera system they have, which is a Canon s100 converted to color infrared, takes a picture every four seconds.
“This provides us a lot of coverage, and the more coverage, the better,” he says.
Agisoft, a Russian software program, splices together the hundreds of images taken to create a mosaic. All of the fields over a 640-acre area are then pulled together into one large image at 1-inch resolution.
“I’m looking at individual plant leaves now,” Price says. “Images are going to get even better in the near future with the new camera systems coming out.”
Finding a device rugged enough to take some abuse and to not cause people to lose valuable equipment like cameras is another area his team is looking at.
The RiteWing Zephyr II is made of expanded polypropylene, which is high-grade engineering foam that has an elastic nature, allowing it to regain its shape.
“It is rugged and flies stable,” Price notes. “It also has fewer parts, which means less breakage.”
On a typical aircraft, the rudder and movable flaps called ailerons on the rear edge of each wing make a plane turn to the left or right. Moving flaps called elevators on the tail make the nose of the plane go up or down.
“The RiteWing Zephyr II has elevons, which combine the functions of the elevator and the aileron,” Price explains.
Besides fewer moving parts, other advantages include less mass, less cost, less draft, and faster control response.
To date, Price says they have spent about $25,000 on their equipment. However, through trial and error, he believes they could build a unit for less than $2,000.
“We tell farmers to expect to pay around $5,000, because they have to buy a radio, which is about $400,” he notes.
As the new owner of a RiteWing Zephyr XL (similar to the Zephyr II but with an 81-inch wing span), Brining has tried several forms of aerial imagery in the past.
“I have used custom-flown, traditional aerial imagery,” he says. “The resolution was poor. The costs were extremely high (around $3.50 per acre per flight), and they didn’t get the flights accomplished in a timely enough fashion to meet my objectives.”
What intrigued him about this technology is its incredible flexibility, speed, and low cost for flights combined with a very high-resolution final product.
“I think the new system will let me make tactical decisions, which have all been done strictly based on ground scouting and sampling,” Brining adds.
He estimates the entire system will cost $5,000 to $7,000.
In the first year, he wants to get the system operational, learn to process images, and use the flights as a tool so his agronomists can make better use of their time by scouting the right parts of the field.
“I think it will also be extremely helpful in locating leaks in my subsurface drip-irrigation systems,” he adds.
Crunching the numbers
According to The Economic Impact of Unmanned Aircraft Systems Integration in the United States, precision agriculture is one of the markets with the largest potential for this technology. The document, which was released by the Association for Unmanned Vehicle Systems International (AUVSI), estimates that in just two years the economic and employment impacts of ag spending in all 50 states will be nearly $2.1 billion and creating more than 21,500 jobs.
“UAS are tools to apply precision agriculture techniques,” says Chris Mailey, vice president of Knowledge Resources for AUVSI. “They are a key piece in the future of precision agriculture.”
However, he cautions, realizing those gains will be tied to certain factors.
“State incentives, like a tax incentive or a test site, may bring more jobs to one state vs. another,” he notes. “Legislation – positively and negatively – may affect the adoption of these devices in the short term. I believe that once any technology – no matter what it is – is proven out, it is much easier to get larger adoption.”
Every year that sales of the technology are delayed, the report says the U.S. stands to lose $10 billion.
With more than 18,000 airports, 750 air traffic control facilities, and 4,500 air navigation facilities, national airspace is a huge system to manage. There are more than 238,000 general aviation aircraft in the system at any time. Maintaining safety in the sky is the FAA’s top mission.
Mailey says it should be the mission of the ag industry, as well.
“Safety is going to be paramount,” he says. “UAS are just like a tractor or a truck. If you take your eyes off of it or do something not very smart, it can be a very, very dangerous device.”