dbh_minradius_ratio_qsm: DBH minimum tree radius ratio TreeQSM

In lmterryn/ITSMe: Individual Tree Structural Metrics

DBH minimum tree radius ratio TreeQSM

Description

Calculates the ratio between the dbh and the minimum tree radius from a TreeQSM.

Usage

dbh_minradius_ratio_qsm(
  treedata,
  cylinder,
  pc = NA,
  buttress = FALSE,
  thresholdR2 = 0.001,
  slice_thickness = 0.06,
  thresholdbuttress = 0.001,
  maxbuttressheight = 7,
  concavity = 4,
  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.
buttress	Logical (default=FALSE), indicates if the trees have buttresses. Only relevant if pc is available.
thresholdR2	Numeric value (default=0.001). Parameter of the dbh_pc function used to calculate the diameter at breast height. Only relevant if the tree point cloud is available and buttress == FALSE.
slice_thickness	Numeric value (default = 0.06). Parameter of the dbh_pc and dab_pc functions used to calculate the diameter at breast height and above buttresses. Only relevant if the tree point cloud is available.
thresholdbuttress	Numeric value (default=0.001). Parameter of the dab_pc function used to calculate the diameter above buttresses. Only relevant if the tree point cloud is available and buttress == TRUE.
maxbuttressheight	Numeric value (default=7). Parameter of the dab_pc function used to calculate the diameter at breast height. Only relevant if the tree point cloud is available and buttress == TRUE.
concavity	Numeric value (default=4) concavity for the computation of the functional diameter using a concave hull based on concaveman. only relevant when a point cloud is provided.
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.

Details

This ratio is defined as "Ratio between the DBH and the minimum of the vertical bin radius estimates" (Akerblom et al., 2017 & Terryn et al., 2020). The vertical bin radius estimates are calculated with vertical_bin_radii_qsm. DBH is calculated with dbh.

Value

The ratio of the dbh and the minimum tree radius.

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

## Not run: 
# Read tree qsm and calculate the dbh minimum tree radius ratio
qsm <- read_tree_qsm(QSM_path = "path/to/qsm.mat")
dmrr <- dbh_minradius_ratio_qsm(
  treedata = qsm$treedata,
  cylinder = qsm$cylinder
)
# with point cloud data
pc_tree <- read_tree_pc(PC_path = "path/to/point_cloud.txt")
dmrr <- dbh_minradius_ratio_qsm(
  treedata = qsm$treedata,
  cylinder = qsm$cylinder, pc = pc_tree
)
# for a buttressed tree
dmrr <- dbh_minradius_ratio_qsm(
  treedata = qsm$treedata,
  cylinder = qsm$cylinder, pc = pc_tree,
  buttress = TRUE
)

## End(Not run)

lmterryn/ITSMe documentation built on Feb. 4, 2025, 2:21 a.m.