Research project relies on unmanned aircraft

Author: Malcolm McDowell Woods

Published Date: 10/8/2021

Categories: Aviation Science Biochemistry Chemistry Environmental Science F1RST Magazine Freshwater Sciences

Drone Program Takes Research to New Heights

Wade into any cool, clear Wisconsin inland lake, and the movement of your legs will create small ripples that radiate out across the surface of the water, slowly and steadily dissipating. But under the surface, your movements are causing a stir as well, as those miniature waves you’ve created undulate through the water. Sediment on the lakebed is kicked up, and the water brieﬂy clouds as particles rise and fall. Underwater vegetation sways like dune grasses in a light breeze.

It all settles again within moments, just a series of ﬂeeting dances set off by each step. Harmless enough. Now imagine that instead of your two feet, it’s a 400-horsepower engine on the back of a boat that has been speciﬁcally designed to direct its energy downward in order to create a large wake.

Wakeboarding is a popular recreational activity on Wisconsin’s lakes. Unlike waterskiing, in which a skier is towed behind a boat and skims along the surface of the water, a wakeboarder zigzags back and forth, attacking the wake created by the boat to get airborne and perform tricks. The bigger the wake created, the more air the rider can catch. Wake surﬁng foregoes the tow rope altogether; the surfer rides a wave created by the boat as it cuts through the water. Again, the bigger the wake, the larger the wave and the longer the ride. To create those waves, watercraft manufacturers speciﬁcally design boats with downward-facing propellers and additional ballast to help weigh down the rear of the boat. Even moving slowly, these boats appear ready to leap out of the water, as the motor’s energy is forced downward to displace water.

MAKING WAVES

Until you zoom in on a map, North Lake looks like two lakes separated by a narrow strip of land running north and south. A closer look reveals it to be a sand bar dividing the lake into a larger eastern body of water and smaller western quarter. It’s the northernmost of a handful of deep lakes scraped across western Waukesha County by glaciers. North Lake totals 438 acres, descends 78 feet deep at its deepest, and is fed by the Big and Little Oconomowoc rivers, a creek and a small channel from tiny Cornell Lake to the south. According to the North Lake Management District (NLMD), there are 238 property owners lining the lakeshore.

It’s a good bet all of them like the idea of preserving the lake’s quality. Many of the homes surrounding the lake have piers or docks of their own, and good weather ﬁnds the residents out enjoying the lake – pontoon boats glide lazily, ﬁshing craft drift on currents, a small ﬂotilla of sailboats harnesses the breeze and swimmers dive from docks and clamber onto ﬂoating offshore platforms. Add in boats towing water skiers and people on ﬂoats and ﬁnally those wave-enhancing watercraft, or wake boats, and you have a lot of human-created activity on the lake. All of which might raise a couple of questions: what is all that activity doing to the lake and how is it affecting water quality?

Tim Tyre is one of the property owners on the lake. He said he’s seen a change in water quality over the years he believes has been caused by several factors, “one of which is we’re stirring up a lot of sediment,” he noted. In 2017, a committee formed by the NLMD instituted safe boater guidelines and conducted annual surveys, which revealed strong support for a more comprehensive water quality study. The presence of wake-creating boats and the more powerful wave-enhancing boats is a controversial issue on many small inland lakes, but there hasn’t been much research conducted to determine their actual impact. How does human behavior impact the quality of a body of water?

Last year, a multi-agency effort to conduct just such research began, examining water quality, wave propagation and shoreline erosion on North Lake. The project was a collaboration between the Southeastern Wisconsin Regional Planning Commission, and Carroll University. Terra Vigilis, a private company specializing in unmanned aircraft systems technology, was recruited to help gather data.

Carroll’s team was led by Joe Piatt, a professor of environmental science, and Mike Mortensen, director of Carroll’s aviation science and unmanned aircraft systems program. (Mortensen and Tyre also work for Terra Vigilis.)

The project last year felt like a really good way to explore what sort of information – data – could be collected using drones, explained Mortensen. Unmanned aircraft systems, or drones, were used to help visually map out the lake and to photographically document any changes to its shoreline. Drones – both airborne and submersible – were also used to help collect water samples for further analysis, study lakebed vegetation and measure wave action underwater. Assisted by faculty, Pio Scholars' students participated in the gathering of data and in creating a report documenting the team’s ﬁndings.

Once that report was presented, there was a lot of interest among lake residents and the Wisconsin Department of Natural Resources for a deeper dive into the data.

“The DNR asked Terra Vigilis to write a grant this year with goals that were more focused on some of the things we learned from last year – more on wave propagation and sediment movement,” said Mortensen. Terra Vigilis oversees this year’s project, while Carroll faculty will conduct the bulk of the research.

North Lake resident Tim Tyre and Carroll professor Mike Mortensen.

An aerial view of North Lake, taken by an unmanned aircraft system.

Carroll student performing analysis in chemistry lab

Biochemistry major Alex Navin analyzes samples in Carroll's chemistry lab.

MULTIDISCIPLINARY APPROACH

Alex Navin, a senior at Carroll majoring in biochemistry with a minor in unmanned aircraft systems, slips on a virtual reality headset and maneuvers an underwater drone away from his position on a pier on North Lake. The bright yellow drone, about the size of a box of breakfast cereal, dives below the surface at his command. The submersible, equipped with bright lights and capable of capturing both video and photographs, is just one of a collection of tools Navin has learned to use, in addition to piloting a drone.

None were on his radar when he entered Carroll. “Professor Piatt reached out to a bunch of students about a project coming up last year,” recalls Navin. “He mentioned there was a lot of drones involved with it, too.” Navin, who is interested in computer science and technology in general, immediately expressed interest.

Piatt jokes that Navin’s experience playing video games has helped prepare him to operate drones. Indeed, the submersible, expertly guided by the senior, nimbly cuts through the water, chasing the occasional curious fish. In his studies for the minor, Navin has learned to operate both the submersible and a variety of unmanned aircraft systems. But the lessons have extended far beyond that, as he has learned coding, data collection and analysis via a variety of onboard sensors and even aviation law.

Navin is eyeing a career in either forensic or environmental science upon graduation, and he’s excited about the way the skills he is learning in the program can be utilized in either field. “I think the way these skills intersect with so many other areas is cool,” he said.

“I’ve gained a lot of different skills,” he recounted later. “I never envisioned doing drone research in my undergraduate studies. And when I have tried to research other schools doing this type of stuff, well, there aren’t really many. This will give me a competitive edge in my career, being able to operate these systems and being able to write code. It brings together a lot of areas in my undergraduate studies, like computer science.”

The interdisciplinary possibilities presented by this minor are both numerous and intentional, according to Mortensen, and a result of the program’s focus on drone technology to gather data. That use has exploded in recent years, as technological advances have resulted in an expanding variety of sensors that can be carried as drone payloads. Sensors carried aloft can analyze plant and water health, search for the presence of specific chemicals and record and measure plumes of sediment created by watercraft. The potential for data collection is immense – as are the varieties of information that can be collected.

For environmental science professor Piatt, the North Lake research project has been a successful collaboration and sparked his thinking. “I’m looking at all this equipment,” he said, “and thinking about how it can impact my teaching and how we can use this new technology in our chemistry labs.” Traditional biochemistry laboratories rely upon bench equipment – large and often expensive machines. “But these microsensors are the future.”

At Carroll, which has rushed headfirst into the information age, the emphasis on data collection and analysis is critical. The university has declared data literacy a crucial skill for all graduates.

Dr. Julio Rivera, the William B. Yersin professor of applied business analytics at the School of Business, points to this research project as further proof of the interdisciplinary role to be played by data analytics skills across campus. The North Lake research team has conferred with the School of Business about the use of ArcGIS, a geographic information mapping application, to help analyze and visually display the data collected. “It is now a cliché to say that we are awash in data,” said Rivera. “It streams into us from every corner.” And drones represent another important data stream.

“The business applications of drone technology are of great interest to us,” said Rivera. “ArcGIS (as well as other GIS programs) allow users to take data (from drones or other sources) that is large, messy, and in incompatible formats and transform it into understandable analysis in the form of maps, images, charts, and tables.”

TELLING THE DATA’S STORY

At North Lake, the research team has collected water samples, measured the depth and strength of underwater waves created by a variety of watercraft, visually recorded changes to the lakebed and shoreline over the course of the summer and generated a LOT of data. Three-dimensional maps were also created to allow the researchers to run simulations and collect additional data.

They also collected their fair share of curiosity. Mortensen said the group has heard from boat owners, boat manufacturers and other lake organizations, all interested in the research. He is careful to explain that this is a research project only – that it will be up to others to interpret that data and craft any policy.

For all involved, that means honestly and accurately telling the story that lives within the data. “We thought a lot about that – about data collection and analysis. Julio (Rivera) talks a lot about strategic data visualization - how do you present the data?” You need someone to tell you what the data means.

That’s how a collaborative project between the aviation science and unmanned aircraft systems and environmental science departments also involves computer science, information technology, data analytics, and even graphic design.

“We’re doing it right at Carroll,” said Mortensen. “We came in at the right time with this program. Five years ago, you didn’t have the numbers of off-the-shelf sensors you could put on the drones to do this sort of research. But it’s feasible now. Thank goodness, Charlie Byler (former arts and sciences dean) and Kevin McMahon (chair of the department of computational and physical science) and others saw that we were in the position at the right time. It’s going to grow.”

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