rLiDAR (version 0.1.1)

LASmetrics: LiDAR-derived metrics

Description

Compute LiDAR metrics that describe statistically the Lidar dataset

Usage

LASmetrics(LASfile, minht, above)

Arguments

LASfile

A LAS standard LiDAR data file

minht

Use only returns above specified height break, e.g. 1.30 m. Default is 1.37 m.

above

Compute covers metrics using specified height break, e.g. 2.5 m. Default is 2 m.

Value

Returns A matrix with the LiDAR-derived vegetation height and canopy cover metrics (see cloudmetrics, in McGaughey, 2014)

See Also

McGaughey, R. 2014. FUSION/LDV: Software for lidar data analysis and visualization. Version 3.41. Seattle, WA: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station.

# List of the LiDAR-derived metrics:

• Total all return count

• Total first return count

• Total all return count above minht

• Return 1 count above minht

• Return 2 count above minht

• Return 3 count above minht

• Return 5 count above minht

• Return 6 count above minht

• Return 7 count above minht

• Return 8 count above minht

• Return 9 count above minht

• HMIN - Maximum Height

• HMAX - Maximum Height

• HMEAN - Mean height

• HMOD - Modal height

• HMEDIAN - Median height

• HSD - Standard deviation of heights

• HVAR - Variance of heights

• HCV - Coefficient of variation of heights

• HKUR - Kurtosis of Heights

• HSKE - Skewness of Heights

• H01TH - 01th percentile of height

• H05TH - 05th percentile of height

• H10TH - 10th percentile of height

• H15TH - 15th percentile of height

• H20TH - 20th percentile of height

• H25TH - 25th percentile of height

• H30TH - 30th percentile of height

• H35TH - 35th percentile of height

• H40TH - 40th percentile of height

• H45TH - 45th percentile of height

• H50TH - 50th percentile of height

• H55TH - 55th percentile of height

• H60TH - 60th percentile of height

• H65TH - 65th percentile of height

• H70TH - 70th percentile of height

• H75TH - 75th percentile of height

• H80TH - 80th percentile of height

• H90TH - 90th percentile of height

• H95TH - 95th percentile of height

• H99TH - 99th percentile of height

• CRR - Canopy relief ratio

• IMIN - Minimum intensity

• IMAX - Maximum intensity

• IMEAN - Mean intensity

• IMOD - Modal intensity

• IMEDIAN - Median intensity

• ISD - Standard deviation of intensities

• IVAR - Variance of heights

• ICV - Coefficient of variation of intensities

• IKUR - Kurtosis of intensities

• ISKE - Skewness of intensities

• I01TH - 1th percentile of intensity

• I05TH - 5th percentile of intensity

• I10TH - 10th percentile of intensity

• I15TH - 15th percentile of intensity

• I20TH - 20th percentile of intensity

• I25TH - 25th percentile of intensity

• I30TH - 30th percentile of intensity

• I35TH - 35th percentile of intensity

• I40TH - 40th percentile of intensity

• I45TH - 45th percentile of intensity

• I50TH - 50th percentile of intensity

• I55TH - 55th percentile of intensity

• I60TH - 60th percentile of intensity

• I65TH - 65th percentile of intensity

• I70TH - 70th percentile of intensity

• I75TH - 75th percentile of intensity

• I80TH - 80th percentile of intensity

• I90TH - 90th percentile of intensity

• I95TH - 95th percentile of intensity

• I99TH - 99th percentile of intensity

• Pentage first returns above above

• Percentage all returns above above

• (All returns above above / Total first returns)*100

• First returns above above

• All returns above above

• Percentage first returns above mean

• Percentage first returns above mode

• Percentage all returns above mean

• Percentage all returns above mode

• (All returns above mean / Total first returns)*100

• (All returns above mode / Total first returns)* 100

• First returns above mean"

• First returns above mode

• All returns above mean

• All returns above mode

Examples

# NOT RUN {
#=======================================================================#
# Example 01: Computing LiDAR metrics for a single LAS file
#=======================================================================#
# Import the LAS data file
LASfile <- system.file("extdata", "LASexample1.las", package="rLiDAR")

# Set the minht and above parameters
minht<-1.37  # meters or feet
above<-2.00  # meters or feet

# LiDAR metrics computation
LiDARmetrics<-LASmetrics(LASfile, minht, above)

#==========================================================================#
# Example 02: Computing Lidar metrics for multiple LAS files within a folder
#==========================================================================#
# Set folder where LAS source files reside
folder=dirname(LASfile)

# Get list of LAS files residing in the folder
LASlist <- list.files(folder, pattern="*.las", full.names=TRUE)

# Set the "minht" and "above" parameters
minht<-1.37  # meters or feet
above<-2.00  # meters or feet

# Creat an empty dataframe in whic to store the LiDAR metrics
getMetrics<-data.frame()

# Set a loop to compute the LiDAR metrics
for ( i in LASlist) {
 getMetrics<-rbind(getMetrics, LASmetrics(i, minht, above))}

# Table of the Lidar metrics
LiDARmetrics<-cbind(Files=c(basename(LASlist)), getMetrics)
head(LiDARmetrics)

# }