Nov 2, 2021

Using LiDAR to quantify effects of Climate Change in Vermont Forests – Documenting Caterpillar Damage

What is the challenge?

The gypsy moth is an invasive species that can devastate forest canopies. In Vermont the gypsy moth is normally kept in check by a fungus, but abnormally dry conditions prevented the fungus from thriving resulting in an explosion of gypsy moth caterpillars.

By June, the region was suffering the largest infestation in 30 years. The caterpillars devoured the leaves on trees, causing bare patches in spots that normally would be lush and green. The University of Vermont Spatial Analysis Lab just happened to be in the right place at the right time to document this phenomenon.

The University of Vermont team has nearly a decade of experience using drone technology, but up until this point, only employed imaging sensors on their drones. Developing an understanding of changes to the forest structure caused by the gypsy moth outbreak required active sensing, so the team turned to YellowScan’s Mapper LiDAR sensor.

Initial outbreak of the caterpillar infestation

Initial outbreak of the caterpillar infestation – Images provided by University of Vermont Spatial Analysis Lab, 2021

“One of the big factors for us was access. It’s really hard to go walk tens or hundreds of acres and figure out what’s happening there, but with the drone, we can map that in maybe 15 to 20 minutes and process that in just a few hours”
Adam Zylka

UAS Team Lead, University of Vermont Spatial Analysis Lab

What about the workflow?

The YellowScan Mapper’s easy-to-use workflow and quick training that UVM-SAL received was critical to the mission’s success. Frontier Precision, a member of YellowScan’s Global Partner Network, arranged for an on-site training session in Vermont.  This timely session and further support from YellowScan gave Adam and his team the confidence and know-how to get their drone and LiDAR solution in the air and gathering data. They collected data at the same location in July during peak defoliation and then again in August as the leaves recovered. The captured photos and point cloud data show a profile comparison of the same area of trees at the site.

Now they have a baseline of data points to compare with in the spring of 2022 when the caterpillars will return. The data is being shared with colleagues in the US Forest Service in an effort to better understand the infestation and to determine any longer-term effects on the forest from this event. The UVM-SAL Team was featured in a television news story, you can find the link here.

Photo of infested zone of forest
Point Cloud data of infested zone of forest

Photo and Point Cloud data of infested zone of forest – Images provided by University of Vermont Spatial Analysis Lab, 2021

“We are thrilled with the experience and data that we collected with the YellowScan Mapper. The LiDAR system has given us a new tool in our arsenal to study and better understand the forests in Vermont”
Jarlath O'Neil-Dunne

Director, University of Vermont Spatial Analysis Lab and USDA Forest Service R&D

What about the LiDAR mission?

The YellowScan Mapper is a purely aerial LiDAR solution that is ideally flown at 70m above ground level. It is designed to fit all professional drones such as the DJI M300 and Acecore Zoe, and comes with an optional integrated camera module. YellowScan Mapper is ideal for topographic mapping projects and is particularly suited for archaeology, forestry, and post-disaster missions. The YellowScan Mapper seamlessly integrates with existing YellowScan software solutions, CloudStation and LiveStation, making it easy to remotely check data while the system is flying, and comprehensively post-process, visualize and export survey data.

YellowScan Mapper on DJI M300 drone

YellowScan Mapper on DJI M300 drone – Images provided by University of Vermont Spatial Analysis Lab, 2021

  • UAS: DJI Matrice 300
  • Sensor: YellowScan Mapper
  • Flight speed: 10 m/s
  • Flight height: 70m AGL
  • Trajectory correction: PPK using CORS station operated by Vermont Agency of Transportation (VTrans)
  • Outputs:
    • LAZ point cloud
      • 500+ ppm2
      • Approx. 45 acre (1 flight)
      • Ground points classified in YellowScan CloudStation software solution
    • DEM /DSM/nDSM
      • ~ 4 cm/pixel GSD
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