Vantage point: Sky's the limit for aerial-obtained data
By Stephanie Jacques
Looking at problems from a different angle can provide the perspective needed to find solutions. Kansas State University researchers are employing this strategy by using unmanned aircraft systems, or small UAS, to gather important data needed to address some of the world’s most pressing problems, including UAS safety, nuisance species and air composition.
K-State researchers also are at looking at how to improve data fusion: the integration of aerial data — including satellites and UAS — to make information more useful.
“UAS enables us to approach data collection in new ways,” said Andrea Meyer, research program manager at the Applied Aviation Research Center at Kansas State University Polytechnic in Salina, where data fusion is a key research area. “With advances in coding and software, the aerial data from UAS — usually in high resolution — can be combined with more traditional sources, such as satellite imagery, to help make data more influential and practical. Automating that process is key to managing data more effectively and efficiently.”
A ray of light
The federal government is among the entities looking for more efficient and reliable methods to collect and analyze data relating to climate.
Through a National Science Foundation grant, Matthew Berg, K-State associate professor of physics, is working on a method to image aerosol particles using UAS. By mounting a miniature mobile laser lab on an unmanned aerial vehicle, Berg may be able to collect holographic images of free-floating aerosol particles in the atmosphere. This may help climate scientists better understand the composition of the atmosphere and if atmospheric particles have the potential to reflect or absorb heat.
“Identifying free-floating particles from light-scattering methods was largely guesswork before, unless you had a sphere,” Berg said. “Now, we get objective size and shape measurements with a quick, contact-free light-scattering method that we can put on an instrument and fly around in the air.”
Berg has already tested the process in the lab using intersecting green and red lasers. The lasers flash for 30 nanoseconds at a time, illuminating the light scattering from the particle and producing a hologram that can be captured by a camera. Not only will this process help identify what is in the air as it is flying through the air, but with further development, it could have the potential to detect airborne biological weapons.
Clearing the airway
UAS operation safety is of growing importance. On average, the Federal Aviation Administration receives around 1,000 non-hobby unmanned aircraft systems registrations every week. Based on registration trends, the FAA estimates that 420,000 small commercial UAS will be sharing the national airspace by 2021, up from 42,000 in 2016. Along with this increase is further development of UAS technology for commercial purposes, such as quicker delivery of packages or lifesaving search and rescue.
Even with the FAA’s first set of rules specifically for UAS flight in national airspace — Code of Federal Regulations Part 107 — UAS flight is still more restricted than manned aircraft, Meyer said. The Applied Aviation Research Center is leading the way on safety with two projects as part of the FAA’s Alliance for System Safety of UAS through Research Excellence, or ASSURE, to create industry standards for how all aspects of the unmanned aircraft system work together before flight and for continued flight as the industry progresses.
“Many of today’s manned aviation regulations were created because of catastrophic accidents,” said Trevor Witt, UAS pilot and data analyst for the center. “The FAA is trying to be proactive and maintain safety with UAS regulations but in a way that it still benefits the economy.”
Both safety projects at the center use the current regulations for manned aircraft as a baseline but adjust for the unique aspects of the entire system: the vehicle, the control station, the data link, the software and even a human operator.
Creating an industry standard for how all these aspects work together is important for continued safety as the industry progresses, Meyer said. The partnership with the FAA also has given the center opportunities to pitch safety plans for some of the regulations, like flying at night, so researchers can collect different types of data for research projects.
A honeysuckle in the haystack
In fall 2016, Witt worked with Ryan Armbrust, forest health and conservation forester at the Kansas Forest Service, an independent agency within K-State Research and Extension, to come up with software protocol to identify an invasive and aggressive plant species. Native to Asia, bush honeysuckle suppresses root regeneration in nearby plants and produces berries that are like junk food for birds. The plant is widespread in Kansas.
“The goal with this project was to use known locations of bush honeysuckle to ‘train’ software so that it could find other concentrations of bush honeysuckle,” Witt said.
After Armbrust confirmed a few ground locations, the team modified a digital camera to block red light and capture near-infrared light, which is invisible to human eyes. They attached the camera to a manned aircraft and flew over Hutchinson, Lawrence, Manhattan, Topeka and Wichita in search of the plant’s unique light reflection signature.
“Bush honeysuckle will stay green through early December,” Armbrust said. “That’s a competitive advantage because it can shade out a lot of its competition, but it also means we can use its strength against it.”
Since the researchers were evaluating entire cities at a time and FAA regulations prevent flying unmanned vehicles over people, Witt flew a Cessna 172 for the beta testing of the software. The camera, which took photos at 12 centimeters per pixel, can also be attached to an unmanned aircraft for smaller sections of land such as a park. The software automatically maps the location of the invasive species so people can spray or remove the plant.
“Having this kind of information may provide an opportunity for some partners to more effectively and strategically manage this invasive plant, and for them, this could be a big advantage over the old anecdotal efforts to understand where the plant is and where treatment should be concentrated,” Armbrust said.
Knowledge is power
As the only U.S. partner in a three-year project with the Plant Biosecurity Cooperative Research Centre in Australia, Brian McCornack, K-State associate professor of entomology, is working with his Australian counterparts to develop an interactive knowledge tree that will help end users decide if current UAS platforms and sensor technologies are worth the investment for managing invasive species.
As a case study for the knowledge tree, McCornack is using UAS to identify sugarcane aphid infestations in grain sorghum — a high-energy grain known for its remarkable drought tolerance and variety of uses in human and animal nutrition. Kansas has historically led the nation in grain sorghum production acres, but according to McCornack, the sugarcane aphid has caused drastic production declines.
“There are estimates of 30-40 percent reduction in sorghum acres planted in Kansas since the addition of sugarcane aphid to the landscape, which affects the farmer’s bottom line,” McCornack said. “This is why early detection and effective pest surveillance programs are vital to Kansas agriculture.”
McCornack said the invasive insect can cause a 70-80 percent yield reduction in sorghum if it is not caught in time, and costs $15-$20 an acre to treat and manage plus time scouting fields for the pest. The use of small UAS shows promise in helping target early infestations by covering a larger amount of ground in a short period of time.
Sugarcane aphids may be small — about 1.5 millimeters — but they come in masses to suck sap out of sorghum plants. They secrete honeydew droplets on the plant’s leaves, causing a black, sooty mold to grow on them. This condition can be easily seen in images from UAS flown just above the canopy. With Witt’s assistance, McCornack can get an aerial perspective of the pest, which could potentially change how a crop field is sampled for infestations and disease.
“UAS provides immediate value to help crop scouts identify problem areas in a sorghum field by providing a new perspective, or vantage point, instead of just what is viewable from eye level as they walk through the field,” Witt said. “They can possibly catch a problem before it gets too big.”
This case study is just one example that McCornack is using to build the knowledge tree. Since the technology is constantly advancing, the knowledge tree will help the agriculture industry decide if the technology has enough immediate benefit or if plant biosecurity programs should continue to wait until UAS has the proper sensor technologies, more tools or more automation.
“We want others to learn about the process that we went through using the diverse case studies we have explored, from fields to forested areas to vineyards,” McCornack said. “UAS technologies have quickly evolved in ways we didn’t anticipate. We feel our interactive knowledge tree will help frame some of the key questions people need to ask before they invest in the technology.”
UAS may not be able to provide automatic prescriptions or solutions to today’s agricultural production problems yet, but researchers, farmers and consultants are finding innovative ways to make the technology’s extra perspective useful and informative, McCornack said.