To measure vegetation in the wild, the researchers installed Microsoft HoloLens as a mixed reality sensor to power their app called VegSense.
A proof-of-concept study by Rice University graduate student Daniel Gorczynski and bioscientist Lydia Beaudrot shows that VegSense could be a suitable alternative to traditional classical field measurements at a low cost.
His study in Methods in Ecology and Evolution shows that the combination of hardware and software excels at quantifying trees in nature, which is a measure of the overall health of a forest.
Gorczynski came up with the idea to test HoloLens, commonly marketed as a productivity tool for manufacturing, healthcare, and education. He developed the open source software for the device and notes that while the combination is less effective at picking up saplings and small branches, there is ample room for improvement.
Gorczynski says he first came across mixed reality sensing as a student at Vanderbilt University and recognized its potential for biological studies. “It seemed like a kind of natural fit,” she says. Gorczynski brought the idea to Beaudrot in 2019 shortly after his arrival at Rice.
The combination of off-the-shelf hardware and custom software costs much less than the lidar-based systems (for “light detection and ranging”) that are most often used in 3D field surveys, says Gorczynski, who developed VegSense on a platform. oriented more towards 3D games and interactive experiences than hard science.
Field tests in Houston’s Memorial Park showed that, at least for mature trees, the smaller solution is just as good. In his case study, VegSense easily detected 48 of 50 such trees in the target area, a circle about 30 feet in diameter that Gorczynski walked, looking up, down, and around to build the 3D database. (“Imagine an asterisk with a circle around it,” he says, describing the pattern of data capture.)
“For this study, we wanted to be really deliberate in trying to replicate more traditional understory vegetation structure measurements,” says Gorczynski. “We try to get that level of detail.”
What you see as you scan the environment is a hologram-like grid pattern that tracks the surfaces of vegetation. “What’s really cool about this is that you can see what the scanner is picking up, but also what points you’ve missed,” says Gorczynski. “The idea is to make the mesh cover as much vegetation as possible because that’s what allows you to get the best scan.”
“The results were so good that Dan quickly redacted them for publication,” says Beaudrot, noting that Gorczynski extended his validation of the kit during a subsequent field trip to Tanzania, the focus of one of 15 tropical forests in a recent study by the tropical jungle made by the group.
“This device can facilitate a lot of great ecological research, particularly because it’s so cost-effective,” she says. “Collection of information on the vegetation in the forest floor right now it’s really hard to do without a lot of manual work or a really expensive lidar system.”
“So this is an innovative and cost-effective device,” says Beaudrot. “It won’t give you the same data resolution as lidar, but this is just the first application. We hope that making VegSense open source for the ecological research community will stimulate all the possible ways it can be developed.”
Northrop Grumman, Conservation International and Rice supported the research.
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