Get 'Rangeland Analysis Platform' (RAP) Grids

Two sets of 'Rangeland Analysis Platform' (RAP) products are available (see source argument). "rap-30m" is Landsat-derived and has approximately 30 meter resolution in WGS84 decimal degrees ("EPSG:4326"). This is the data source that has been used in the 'rapr' package since 2022. A newer source (2025), "rap-10m", is Sentinel 2-derived and has 10 meter resolution in the local WGS84 UTM zone ("EPSG:326XX", where XX is the two digit UTM zone number). See Details for the products and bands available for the different resolutions and sources.

Usage

get_rap(
  x,
  years,
  product,
  filename = NULL,
  ...,
  source = "rap-30m",
  version = "v3",
  vrt = FALSE,
  sds = FALSE,
  legacy = FALSE,
  verbose = TRUE
)

Arguments

x: Target extent. Derived from an sf, terra, raster or sp object or numeric vector containing xmin, ymax, xmax, ymin in WGS84 decimal degrees (longitude/latitude, "EPSG:4326").
years: integer. Year(s) to query. Products are available from 1986 (source="rap-30m") or 2018 (source="rap-10m") up to the year prior to the current year, based on availability of the Landsat and Sentinel 2 source data.
product: Target data: "vegetation-biomass", "vegetation-cover", and/or "vegetation-npp" for source="rap-30m"; "pft" (plant functional type cover), "gap" (canopy gap), "arte" (Artemisia spp. cover), "iag" (invasive annual grass cover), or "pj" (pinyon juniper cover) for source="rap-10m".
filename: Output filename (optional; default stores in temporary file or in memory, see terra::tmpFiles())
...: Additional arguments passed to internal query function and terra::writeRaster() (or terra::vrt() when vrt=TRUE)
source: Grid sources. Options include "rap-30m" (default; Landsat) and "rap-10m" (Sentinel 2).
version: Target version: "v3" and/or "v2" (for "rap-30m"). Currently ignored for source="rap-10m".
vrt: logical. Short circuit to return Virtual Raster Dataset (VRT) for selected grids via terra::vrt(). Default: FALSE. Note: gdalbuildvrt does not support heterogeneous projection systems, so this option is not compatible with source="rap-10m" over multiple UTM zone areas of interest.
sds: logical. Return data as a SpatRasterDataset? Helpful for results containing multiple years and products. Default FALSE returns a SpatRaster object.
legacy: logical. Use legacy (gdal_translate) method? Default: TRUE (applies only to source="rap-30m").
verbose: logical. Print messages indicating progress? Default: TRUE. For legacy=TRUE progress is shown using utils::txtProgressBar().

Value

a SpatRaster containing the requested product layers by year. If sds=TRUE a SpatRasterDataset where each SpatRaster contains only one product (possibly with multiple years)

Details

Sources, Products, and Band Information

For "rap-30m" you can query several Landsat derived annual biomass, cover, and Net Primary Productivity products from 1986 to present:

product = "vegetation-biomass" returns two layers per year:
- 2 Bands:"annual forb and grass", "perennial forb and grass" (lbs / acre)
product = "vegetation-cover" returns six layers per year:
- 6 Bands: "annual forb and grass", "bare ground", "litter", "perennial forb and grass", "shrub", "tree" (% cover)
product = "vegetation-npp" returns four layers per year:
- 4 Bands: "annual forb and grass", "perennial forb and grass", "shrub", "tree" (NPP; kg*C/m^2)

For "rap-10m" you can query several Sentinel 2 derived cover products at 10 meter resolution from 2018 to present:

product = "pft" returns fractional cover estimates of plant functional types:
- 6 Bands: "annual forb and grass", "bare ground", "litter", "perennial forb and grass", "shrub", "tree" (% cover)
product = "gap" returns canopy gap estimates for four canopy gap size classes:
- 4 Bands: "Gaps 25-50 cm", "Gaps 51-100 cm", "Gaps 100-200 cm", "Gaps >200 cm" (% cover)
product = "arte" returns cover estimates of Artemisia species, including A. arbuscula, A. cana, A. nova, A. tridentata, and A. tripartita.
- 1 Band: "Artemisia spp." (% cover)
product = "iag" returns fractional cover estimates of Bromus tectorum, B. arvensis, B. rubens, B. hordeaceus, Eremopyrum triticeum, Schismus spp., Taeniatherum caput-medusae, and Ventenata dubia.
- 1 Band: "invasive annual grass" (% cover)
product = "pj" returns fractional cover estimates of Juniperus monosperma, J. occidentalis, J. osteosperma, J. scopulorum, Pinus edulis, and P. monophylla.
- 1 Band: "pinyon-juniper" (% cover)

Temporary Files

Large requests may generate intermediate objects that will be stored as temporary files. See terra::tmpFiles() to view the file paths. These files will be removed when an R session ends.

Alternate Specification of Area of Interest

In lieu of a spatial object from {terra}, {raster}, {sf} or {sp} packages you may specify a bounding box using a numeric vector containing the top-left and bottom-right coordinates (xmin, ymax, xmax, ymin) in WGS84 longitude/latitude decimal degrees. This corresponds to the conventional order used in the gdal_translate -projwin option. e.g. get_rap(x = c(-120, 37, -119.99, 36.99), ...).

(1: xmin, 2: ymax)--------------------------|
        |                                   |
        |         TARGET EXTENT             |
        |  x = c(xmin, ymax, xmax, ymin)    |
        |                                   |
        |---------------------------(3: xmax, 4: ymin)

Native Resolution and Projection Systems

Native cell resolution of "rap-30m" is approximately 30m x 30m in WGS84 geographic coordinate system (longitude, latitude). Native cell resolution of "rap-10m" is 10m x 10m in the local (projected) WGS84 Universal Transverse Mercator (UTM) system.

For "rap-10m" requests spanning multiple UTM zones, either pass a SpatRaster object as x or specify template argument. In lieu of a user-specified grid system for multi-zone requests, a default CONUS Albers Equal Area projection ("EPSG:5070") with 10 m resolution will be used. See rap_projection() for options and details.

References

See citation("rapr") for all references related to Rangeland Analysis Platform products.