gediWFSimulator: Simulate GEDI-like full waveforms from airborne laser scanning data

Description

This portable implementation follows the core gediRat algorithm: Gaussian footprint weighting, optional return-density normalization, vertical binning, pulse convolution, separation of LAS class 2 ground returns, and unit-integral normalization. Vectorized binning replaces the original point loop while avoiding its native GSL/GDAL build stack.

Usage

gediWFSimulator(
  input,
  output = tempfile(fileext = ".h5"),
  ground = TRUE,
  ascii = FALSE,
  waveID = NULL,
  coords = NULL,
  listCoord = NULL,
  gridBound = NULL,
  gridStep = 30,
  pSigma = -1,
  pFWHM = 15,
  pRes = NULL,
  fSigma = 5.5,
  res = 0.15,
  decimate = 1,
  maxBins = 1024L,
  countOnly = FALSE,
  method = c("count", "intensity", "fraction"),
  normalize = TRUE,
  density_res = 1.5,
  intensity_threshold = 6e-04,
  noise = 0,
  keepOld = FALSE,
  seed = NULL,
  ...
)

Value

A gedi.level1b object, or a waveform table when ascii=TRUE.

Arguments

input: LAS/LAZ paths, a lidR::LAS, SpatVector, or table with X/Y/Z.
output: Output HDF5 path.
ground: Retained for compatibility; ground returns remain in the waveform.
ascii: Return/write a simple ASCII waveform instead of HDF5.
waveID: Optional waveform identifiers.
coords: A coordinate pair or matrix of footprint centers.
listCoord: Text file containing footprint centers.
gridBound: Optional c(xmin, xmax, ymin, ymax) simulation grid.
gridStep: Grid spacing in input coordinate units.
pSigma: Pulse sigma in meters. A negative value derives it from pFWHM.
pFWHM: Pulse full width at half maximum in nanoseconds.
pRes: Pulse sampling resolution. The default uses res, matching gediRat unless its -pRes option is supplied.
fSigma: Footprint sigma in input coordinate units.
res: Vertical waveform resolution.
decimate: Probability of retaining an ALS return.
maxBins: Maximum number of waveform bins.
countOnly: Use count-based returns rather than ALS intensity. Gaussian footprint weights are still applied.
method: Waveform contribution: "count", "intensity", or "fraction". countOnly = TRUE selects "count" for compatibility.
normalize: Correct for local ALS sampling density, as in the original simulator's default behavior.
density_res: Cell size used for sampling-density normalization.
intensity_threshold: Smallest retained Gaussian footprint weight.
noise: Relative Gaussian noise standard deviation. For example, noise = 0.03 adds noise with a standard deviation equal to three percent of the waveform maximum. Zero leaves the waveform unchanged.
keepOld: Do not overwrite an existing output file.
seed: Optional random seed.
...: Compatibility arguments accepted from the original simulator.

References

Hancock et al. (2019) tools:::Rd_expr_doi("10.1029/2018EA000506")