gridStatsLevel2AM: Compute Grids with Descriptive Statistics of GEDI derived...

In carlos-alberto-silva/rGEDI: NASA's Global Ecosystem Dynamics Investigation (GEDI) Data Visualization and Processing

Compute Grids with Descriptive Statistics of GEDI derived Elevation and Height Metrics (Level2A)

Description

This function computes a series of user defined descriptive statistics within each grid cell for GEDI derived Elevation and Height Metrics (Level2A)

Usage

gridStatsLevel2AM(level2AM, func, res)

Arguments

level2AM	A GEDI Level2AM object (output of getLevel2AM() function). An S4 object of class "data.table".
func	The function(s) to be applied to each cell
res	Spatial resolution in decimal degrees for the output stars raster layer

Value

Return a stars raster layer(s) of selected GEDI Elevation and Height Metric(s)

See Also

https://lpdaac.usgs.gov/products/gedi02_av002/

Examples

# specify the path to GEDI level2A data (zip file)
outdir <- tempdir()
level2A_fp_zip <- system.file("extdata",
  "GEDI02_A_2019108080338_O01964_T05337_02_001_01_sub.zip",
  package = "rGEDI"
)

# Unzipping GEDI level2A data
level2Apath <- unzip(level2A_fp_zip, exdir = outdir)

# Reading GEDI level2A data (h5 file)
level2a <- readLevel2A(level2Apath = level2Apath)

# Get GEDI derived Elevation and Height Metrics
level2AM <- getLevel2AM(level2a)
head(level2AM)

#' Define your own function
mySetOfMetrics <- function(x) {
  metrics <- list(
    min = min(x), # Min of z
    max = max(x), # Max of z
    mean = mean(x), # Mean of z
    sd = sd(x) # Sd of z
  )
  return(metrics)
}

#' Computing a serie of GEDI metrics
ZTstats <- gridStatsLevel2AM(
  level2AM = level2AM,
  func = mySetOfMetrics(elev_highestreturn),
  res = 0.005
)
plot(ZTstats)

#' Computing the maximum of RH100 only
maxRH100 <- gridStatsLevel2AM(level2AM = level2AM, func = mySetOfMetrics(rh100), res = 0.0005)
plot(maxRH100)

#' Computing the mean of ZG only
ZGmean <- gridStatsLevel2AM(level2AM = level2AM, func = mean(elev_lowestmode), res = 0.005)
plot(ZGmean)

close(level2a)

carlos-alberto-silva/rGEDI documentation built on Oct. 18, 2024, 4:46 a.m.