3D Modeling of Light Interception in Heterogeneous Forest Canopies using Ground-based LiDAR Data

International Journal of Applied Earth Observation and GeoinformationInternational Journal of Applied Earth Observation and Geoinformation, Volume 13, Issue 5, October 2011, Pages 792-800

Dimitry Van der Zandea, Jan Stuckens, Willem W. Verstraeten, Simone Mereu, Bart Muys, and Pol Coppin

“Highlights:

  • Voxel-based Light Interception Model to estimate forest canopy/radiation interactions.
  • Estimation of the percentage of above canopy light at any point in 3D canopy.
  • Comparison with reference data yielded a mean absolute error of 5.78%.

“A methodology is presented that describes the direct interaction of a forest canopy with incoming radiation using terrestrial LiDAR based vegetation structure in a radiative transfer model. The proposed ‘Voxel-based Light Interception Model’ (VLIM) is designed to estimate the Percentage of Above Canopy Light (PACL) at any given point of the forest scene. First a voxel-based representation of trees is derived from terrestrial LiDAR data as structural input to model and analyze the light interception of canopies at near leaf level scale. Nine virtual forest stands of three species (beech, poplar, plantain) were generated by means of stochastic L-systems as tree descriptors. Using ray tracer technology hemispherical LiDAR measurements were simulated inside these virtual forests. The leaf area density (LAD) estimates derived from the LiDAR datasets resulted in a mean absolute error of 32.57% without correction and 16.31% when leaf/beam interactions were taken into account. Next, comparison of PACL estimates, computed with VLIM with fully rendered light distributions throughout the canopy based on the L-systems, yielded a mean absolute error of 5.78%. This work shows the potential of the VLIM to model both instantaneous light interception by a canopy as well as average light distributions for entire seasons.”