edu.ucar.opensky::articles:44014 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-24T17:43:33.928211 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.net/ark:/85065/d7bg2tfk https://doi.org/10.5281/zenodo.14983546 https Related Audiovisual #1 Videos of tree sway before, during, and after a snow unloading event on Snoqualmie Pass, WA https://doi.org/10.5281/zenodo.14977623 https Related Dataset #1 Video tree sway data for a subalpine fir tree in Niwot Ridge, Colorado https://doi.org/10.5281/zenodo.5149308 https Related Dataset #2 Multi-year measurements of tree motion from an accelerometer on a fir tree near Niwot Ridge, Colorado https://doi.org/10.5281/zenodo.7988211 https Related Dataset #3 Video and accelerometer tree sway data for an oak tree in Trout Lake, Wisconsin https://doi.org/10.5281/zenodo.7988227 https Related Dataset #4 Video and accelerometer tree sway data for two ponderosa pine trees in the Manitou Experimental Forest, Colorado https://doi.org/10.5281/zenodo.14940621 https Related Software #1 j-amma/swayfreq: v2.0.0 Measuring tree sway frequency with videos for ecohydrologic applications: Assessing the efficacy of Eulerian processing algorithms 2025-10-01T00:00:00Z publication https://n2t.net/ark:/85065/d7bg2tfk https://doi.org/10.1016/j.agrformet.2025.110751 Ammatelli, J. H. author Gutmann, Ethan D. author Bush, S. A. author Barnard, H. author Ciruzzi, D. M. author Loheide, S. P. author Raleigh, M. S. author Lundquist, J. D. author UCAR/NCAR - Library publisher Measurements of tree sway frequency can be used to quantify important ecohydrologic processes, such as drought stress and canopy interception, that otherwise require expensive measurement techniques. However, existing instruments used to measure tree sway lack spatial scalability. We investigate whether the virtual vision sensor and multilevel binary thresholding video processing algorithms can be used to accurately extract tree sway frequency at multiple points in a video camera field of view to enable scalable measurements of ecohydrologic processes. Comparing sway frequencies extracted from video and accelerometer data at three sites, we show that for 30–60 second videos, the video processing algorithms can reproduce 30-minute accelerometer sway frequencies with ±0.02 Hz accuracy. The results suggest that video processing algorithms may be suitable for applications where changes in sway frequency are on the order of tenths of hertz or larger, for example the measurement of snow intercepted in tree canopies. Further work is needed to clarify the accuracy of the algorithms when applied to longer videos, which may be required to monitor processes that result in more subtle changes in sway frequency, such as diurnal changes in tree water content and impacts from drought stress. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication <span style="font-family:Arial;font-size:10pt;font-style:normal;font-weight:normal;" data-sheets-root="1">Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.</span> None eng geoscientificInformation