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Download and process GEDI L4B gridded biomass data

download_gedi_l4b.Rd

Downloads, processes, and saves GEDI L4B Gridded Biomass data for a specified region of interest. The function retrieves data via the ORNL DAAC STAC API, filters for a specified band, creates a data cube, and saves the result as a GeoTIFF.

Usage

download_gedi_l4b(
  roi = NULL,
  gedi_l4b_folder = "data/GEDI_L4B/",
  collection = "GEDI_L4B_Gridded_Biomass_V2_1_2299_2.1",
  gedi_l4b_resolution = 0.001,
  gedi_l4b_band = "MU"
)

Arguments

roi

An sf object representing the region of interest. If NULL, the global extent of available GEDI L4B data is used.

gedi_l4b_folder

Character, the folder to save the downloaded GeoTIFF file. Default is "data/GEDI_L4B/".

collection

Character, the STAC collection ID for GEDI L4B data. Default is "GEDI_L4B_Gridded_Biomass_V2_1_2299_2.1".

gedi_l4b_resolution

Numeric, the spatial resolution of the processed output GeoTIFF in degrees. The native resolution of the GEDI L4B gridded dataset is 1 km, approximately 0.001 degrees at the equator. Default is 0.001.

gedi_l4b_band

Character, the band to filter for. See options in the Details section below. Default is "MU".

Value

Character, the file path to the processed GeoTIFF file.

Details

This function requires a valid Earthdata Login account and the corresponding credentials Ensure that you have set up your Earthdata Login credentials by either:

  • Setting the EDL_USER and EDL_PASS environment variables in a .Renviron file.

  • Running earthdatalogin::edl_netrc(username = EDL_USER, password = EDL_PASS) with your Earthdata Login username and password.

The available bands are based on GEDI L4B Gridded Biomass Density Version 2.1 documentation:

  • "MU": Mean aboveground biomass density (MU): Estimated mean AGBD for the grid cell, including forest and non-forest

  • "SE": Mean aboveground biomass density standard error (SE): Standard Error of the mean estimate, combining sampling and modeling uncertainty

  • "PE": Standard error as a fraction of the estimated mean AGBD. If >100%, the cell values are truncated to 100.

  • "V1": Variance component 1 (V1)

  • "V2": Variance component 2 (V2)

  • "QF": Quality flag

  • "NS": Number of samples

  • "MI": Mode of interference

  • "PS": Prediction stratum

  • "NC": Number of clusters

Consult the reference below for more details about the bands.

References

Dubayah, R., et al. (2022). GEDI L4B Gridded Biomass Data, Version 2.1. NASA Earthdata.

Examples

if (FALSE) { # \dontrun{
  # Example usage with a defined ROI:
  # Define ROI over the Amazon Basin
  roi <- sf::st_as_sf(data.frame(y = c(-10, 0), x = c(-70, -60)), coords = c("x", "y"), crs = 4326)
  # Downloads biomass data for the defined region of interest
  output_file <- download_gedi_l4b(roi = roi, gedi_l4b_band = "MU")
  print(output_file)
} # }