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Harvard Forest REU Symposium Abstract 2010
- Title: Processing digital webcam images to generate a clear phenological signal of forest canopies
- Author: Adam Young (SUNY College of Environmental Science and Forestry)
- Abstract:
Phenology is the study of recurring life cycle events. Previous phenological studies have most often used direct field observations or satellite remote sensing. Digital webcams have the potential to become an effective tool for measuring the phenology of forest canopies. We used the Phenocam website (http://klima.sr.unh.edu/) to download pictures taken throughout the year from several coniferous and deciduous sites. Annual and diurnal time series were evaluated at each site. We determined an appropriate Region of Interest for each site from which Red, Blue, and Green color channels were extracted. Specified vegetation indices, excess green and percent green, were calculated using these extracted color channels. Bad weather and early morning pictures had lower and much more scattered vegetation index values, providing a less clear signal. These images were filtered out using a moving window that calculated the 90th percentile and a running mean. We developed an effective processing algorithm that uses the vegetation indices and filters out the bad weather days. This algorithm provides a clear phenological model. Understanding the structure and function of forests can be greatly increased by examining forest canopy dynamics. The ability and versatility in processing images supports the use of webcams in studying the phenology of different ecosystems.
- Research Category: Ecological Informatics and Modelling; Group Projects
- Figures: Harvard 2009.jpg
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