Abstract
A microcomputer based system for the semi-automatic analysis of hemispherical canopy photos is described and evaluated. Images are transferred from film by a video camera to a digitizer for processing. Our program calculates diffuse and direct site factors (proportions of unobstructed radiation) according to Anderson's methods. These factors are used to estimate absolute amounts of radiation on a horizontal, subcanopy surface from measured or estimated values in the open. Additional indices calculated include the proportion of open canopy in the entire image and in the solar band, the cardinal octants, and 20 concentric rings plus a frequency histogram of potential sunfleck duration. About 20 photos can be processed in an hour. The program was designed for large-scale studies correlating plant biology and distribution or animal behavior with radiation regimes where time scales of several weeks or longer are of interest. Consistency and accuracy of estimates of mean daily global radiation by different operators permit meaningful intersite comparisons.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
