With Green Seed Funding, Students Set CA Up for Aerial Environmental Monitoring
Technology became a pathway to ecology for Quinn Williams ’25 and Carey Cai ’25 in their final semesters at Concord Academy. Last year, interested in electrical engineering, they had been looking into building a fixed-wing 3D-printed drone and were considering practical applications for the project. When they learned about the critical role wetlands play in maintaining healthy ecosystems, they wondered if they could use such a vehicle to map local waterways and track algae blooms from the air. After some research, they realized an ideal tool for this purpose already existed, but it wasn’t within their reach. That’s when the Class of 1972 Green Seed Fund came into the picture.
This alum-sponsored fund awards grants to students pursuing environmentally impactful projects at CA. This year, the fund supported Quinn and Carey’s proposal to purchase a DJI Mavic 3M aerial surveying drone for the school. Designed for agricultural monitoring, this remote-controlled quadcopter is equipped with a standard camera and multispectral imaging, enabling photography in near-infrared and red-edge wavelengths of light that aren’t visible to the human eye. The drone also has remote sensing features that can produce data to measure plant health using the Normalized Difference Vegetation Index (NDVI), a metric typically employed to monitor vegetation changes, drought, and other indicators of ecological health.
In the fall semester, Quinn and Carey met with Concord’s director of natural resources to discuss how their data could help with the town’s conservation efforts. While it became clear that such a partnership would take some time to start, they turned their attention to mapping the school grounds and setting up a system for tracking seasonal vegetation changes on campus. (It’s a project well-aligned with existing interests. Since 2007, faculty member Jodi Pickle has been photographing the landscape behind CA’s Chapel and measuring variables to analyze local environmental health, among them the date of a maple tree’s first leaf.)
The drone arrived in December, and the students started doing flight tests around campus. Quinn, whose interest runs toward software, says he appreciated how easy the Mavic was to fly: “Just map out an area you want to collect data from, click ‘fly,’ and it’ll collect all the images.” The data analysis, he adds, is considerably more complicated.
He has been working on a process called unsupervised segmentation: comparing different indices calculated from the spectral data with data points for certain species along that spectrum. It’s a way of using algorithms to classify different areas of the image as particular species. “What that allows us to do, from one year to another, is to notice, ‘Oh, there’s a lot of this one,’” he says. “So if you have an invasive species and you notice an uptick, then you can take action to mitigate that.” He’s been using open-source data from Concord’s bioregion to refine their model.
A rainy, windy spring limited their ability to conduct regular campus scans, but they had plenty of opportunities to conduct test flights and start mapping out a consistent data collection and preparation process. The data-rich images the drone produces will allow for the creation of detailed environmental maps and will make it possible for students and faculty to track and analyze changes in foliage, land, water quality, and other natural features over the long term.
Carey, who has experience making his own remote-controlled planes, says the visual data a drone can gather, flying 8 meters from the ground, is of much higher resolution than what satellites can capture. He demonstrates, interpreting a set of their test images. “The drone captures images in the red edge—a spectrum of light that humans can’t see but yet encodes valuable information about the photosynthesis process in plants,” he explains. “So you can get information about which plants are photosynthesizing more than others, or essentially how healthy they are.” Plants with a lot of chlorophyll show red in the multispectral imaging. In winter, leafless deciduous trees don’t absorb red light and appear white.
Science teacher and Environmental Sustainability Lead Chris Labosier says he’s looking forward to seeing how this technology could contribute to his ecology class, among other uses. “It’s a great data collection tool with a ton of potential,” he says. “This is a perfect example of what the Green Seed Fund was established to support—not just a finite project, but a learning opportunity that could continue to transform what’s possible for us.”
Quinn also reflected on the project this semester for the final assignment in his English course, Eco-Literature: Locating the “I” in Environment. “My passion is engineering, and I think this is a great way of connecting to my surroundings in Concord—the wetlands and the places I pass every single day—and giving them more attention,” he says. In the final weeks of school, he is preparing the data to transfer to upcoming student leaders and creating a repository of the data processing techniques he and Carey used.
“I give them a lot of credit,” Labossier says. “They have been thinking all along about how to leave this in a good space for someone else to come into. I’m excited for what this could become in the future.”’
Compiled from multiple pictures taken on March 12 using the drone, these orthomosaic images depict the same view of CA’s main campus. Left: the light spectrum visible to the human eye. Right: an NDVI image, in which plants producing chlorophyll appear red.
