Crown diameter height ratio TreeQSM — crown_diameterheight_ratio

Calculates the ratio between the crown diameter and the crown height from a TreeQSM (Akerblom et al., 2017 & Terryn et al., 2020).

Usage

crown_diameterheight_ratio_qsm(treedata, cylinder, pc = NA, dtm = NA, r = 5)

Arguments

treedata: Treedata field of a TreeQSM that is returned by read_tree_qsm.
cylinder: Cylinder field of a TreeQSM that is returned by read_tree_qsm.
pc: The tree point cloud as a data.frame with columns X,Y,Z. Output of read_tree_pc. Default is NA and indicates no tree point cloud is available.
dtm: The digital terrain model as a data.frame with columns X,Y,Z (default = NA). If the digital terrain model is in the same format as a point cloud it can also be read with read_tree_pc. only relevant when a point cloud is provided.
r: Numeric value (default=5) r which determines the range taken for the dtm. Should be at least the resolution of the dtm. Only relevant when a dtm is provided.

Value

The ratio of the crown diameter and crown height.

Details

The crown diameter is the maximum radii of the vertical bin radius estimates that are calculated with vertical_bin_radii_qsm. The crown height is the vertical distance between the highest and the lowest crown cylinder and is obtained from crown_height_qsm multiplied with the tree_height.

References

Akerblom, M., Raumonen, P., Makipaa, R., & Kaasalainen, M. (2017). Automatic tree species recognition with quantitative structure models. Remote Sensing of Environment, 191, 1-12.

Terryn, L., Calders, K., Disney, M., Origo, N., Malhi, Y., Newnham, G., ... & Verbeeck, H. (2020). Tree species classification using structural features derived from terrestrial laser scanning. ISPRS Journal of Photogrammetry and Remote Sensing, 168, 170-181.

Examples

if (FALSE) {
# Read tree qsm and calculate the crown diameter height ratio
qsm <- read_tree_qsm(QSM_path = "path/to/qsm.mat")
cdh_ratio <- crown_diameterheight_ratio_qsm(
  treedata = qsm$treedata,
  cylinder = qsm$cylinder
)
# with point cloud data
pc_tree <- read_tree_pc(PC_path = "path/to/point_cloud.txt")
cdh_ratio <- crown_diameterheight_ratio_qsm(
  treedata = qsm$treedata,
  cylinder = qsm$cylinder,
  pc = pc_tree
)
}