dbh: Diameter at breast height/above buttresses

In lmterryn/ITSMe: Individual Tree Structural Metrics

Diameter at breast height/above buttresses

Description

Returns the diameter at breast height or diameter above buttresses.

Usage

dbh(
  treedata,
  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.
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 if the 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.
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

If the tree point cloud is available the calculations are based on the point cloud (most accurate). In this case the diameter at breast height (dbh) or diameter above buttresses (dab) is calculated with dbh_pc or dab_pc respectively. If the tree point cloud is not available the dbh is based on the treeQSM with dbh_qsm. When the bottom of the point cloud is incomplete or obstructed you can choose to add a digital terrain model as an input which is used to estimate lowest point of the point cloud in order to obtain slices at the correct height of the tree.

Value

The dbh or dab in meters.

Examples

## Not run: 
qsm <- read_tree_qsm(QSM_path = "path/to/qsm.mat")
DBH <- dbh(treedata = qsm$treedata)
pc_tree <- read_tree_pc(PC_path = "path/to/point_cloud.txt")
DBH <- dbh(treedata = qsm$treedata, pc = pc_tree, buttress = TRUE)

## End(Not run)

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