stdmetrics

stdmetrics and associated function provide an easy way to compute many common metrics. This page provide a quick description of each predefined metric if their name associated with the documentation are not enough explicit.

LASfile <- system.file("extdata", "Megaplot.laz", package="lidR")
lidar = readLAS(LASfile, all = TRUE)

# Compute all the predefined functions
lidar %>% grid_metrics(stdmetrics(X,Y,Z,Intensity, ScanAngle, ReturnNumber, Classification, pulseID, dz = 1))

# Super convenient shortcut
lidar %>% grid_metrics(.stdmetrics)

Standard metrics list

• n: number of points
• area: approximative actual area of a raster

• angle: average absolute scan angle
• zmax: maximum height
• zmean: mean height
• zsd: standard deviation of height distribution
• zskew: skewness of height distribution
• zkurt: kurtosis of height distribution
• zentropy: entropy of height distribution (see function entropy)
• zqx: x th percentile of height distribution
• zpcumx: cumulative percentage of return in the xth layer according to Wood et al. 2008 (see metrics named d1,d2, ...)

with the probability distribution of elevations

• itot: sum of intensities for each return
• imax: maximum intensity
• imean: mean intensity
• isd: standard deviation of intensity
• iskew: skewness of intensity distribution
• ikurt: kurtosis of intensity distribution
• ipground: percentage of intensity returned by points classified as "ground"
• ipcumzqx: percentage of intensity returned below the xth percentile of height

• ip1st: percentage of intensity returned by 1st returns
• ip2nd: percentage of intensity returned by 2nd returns
• ip3rd: percentage of intensity returned by 3rd returns
• ipxth: percentage of intensity returned by xth returns
• pxth: percentage xth returns
• pground: percentage of returns classified as "ground"
• ppulsexreturn: percentage of pulse with x returns