FindTreesCHM {rLiDAR} | R Documentation |
Detects and computes the location and height of individual trees within the LiDAR-derived Canopy Height Model (CHM). The algorithm implemented in this function is local maximum with a fixed window size.
FindTreesCHM(chm,fws,minht)
chm |
A LiDAR-derived Canopy Height Model (CHM) raster file. |
fws |
A single dimension (in raster grid cell units) of fixed square window size, e.g. 3, 5, 7 and so on. Default is 5. |
minht |
Height threshold. Detect individual trees above specified height threshold, e.g. 1.37, 2.0, 3.5 m and so on. Default is 1.37 m. |
Returns A matrix with four columns (tree id, xy coordinates, and height).
Carlos Alberto Silva
# Importing the LiDAR-derived CHM raster file data(chm) # or set a CHM. e.g. chm<-raster("CHM_stand.asc") # Smoothing CHM schm<-CHMsmoothing(chm, "mean", 5) # Setting the fws: fws<-5 # dimention 5x5 # Setting the specified height above ground for detectionbreak minht<-8.0 # Getting the individual tree detection list treeList<-FindTreesCHM(schm, fws, minht) summary(treeList) # Plotting the individual tree location on the CHM library(raster) plot(chm, main="LiDAR-derived CHM") library(sp) XY<-SpatialPoints(treeList[,1:2]) # Spatial points plot(XY, add=TRUE, col="red") # plotthing tree location