lidR (version 1.2.0)

grid_tincanopy: Canopy height model based on a triangular irregular network.

Description

Interpolation of a triangular irregular network constructed from first returns. This function enables use of the pit-free algorithm developed by Khosravipour et al. (see reference).

Usage

grid_tincanopy(.las, res = 0.5, thresholds = c(0, 2, 5, 10, 15),
  max_edge = 0.5)

Arguments

.las

A LAS object

res

numeric resolution

thresholds

numeric array. Set of height threholds. If thresholds = 0 the algorithm is a strict rasterizaton of the triangulation of the first returns. However, if an array is passed to the function it becomes the Khosravipour et al. pit-free algorithm.

max_edge

numeric. Maximum edge-length of a triangle in the Delaunay triangulation used to constrain the pit-free algorithm (see reference).

Value

An object of class lasmetrics

References

Khosravipour, A., Skidmore, A. K., Isenburg, M., Wang, T., & Hussin, Y. A. (2014). Generating pit-free canopy height models from airborne lidar. Photogrammetric Engineering & Remote Sensing, 80(9), 863-872.

Examples

# NOT RUN {
LASfile <- system.file("extdata", "Tree.laz", package="lidR")
las = readLAS(LASfile, Classification = FALSE, Intensity = FALSE, filter = "-drop_z_below 0")

# Basic triangulation and rasterization
chm1 = grid_tincanopy(las, thresholds = 0)

# Khosravipour et al. pitfree algorithm
chm2 = grid_tincanopy(las, thresholds = c(0,2,5,10,15), max_edge = 1)

plot(chm1)
plot(chm2)
# }