The gapfraction package implements a new barycentric interpolation spike-free canopy height model (CHM) algorithm based on Khosravipour et al. (2013)1 and (2016)2, in addition to two new LiDAR metrics of canopy gap fraction (\(P_o\)), several individual tree crown (ITC) detection algorithms, canopy distance and direction metrics, effective leaf area index (\(L_e\)) and apparent clumping index (\(ACI\)) estimation methods. Four mathematical fisheye (hemispherical) lens models are implemented: equi-angular, equi-distant, stereographic, and orthographic. Finally, a new radial.grid function is included for polar plots, while a modified sun path plotting function is also provided. An alphabetical list of functions contained in the gapfraction package is provided below.

  1. Khosravipour et al. (2013) Development of an algorithm to generate a LiDAR pit-free canopy height model.

  2. Khosravipour et al. (2016) Generating spike-free digital surface models using LiDAR raw point clouds: A new approach for forestry applications.