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Download specific assets from a set of STAC items

Source: R/download.R
rsi_download_rasters.Rd

Download specific assets from a set of STAC items

Usage

rsi_download_rasters(
  items,
  aoi,
  asset_names,
  sign_function = NULL,
  merge = FALSE,
  gdalwarp_options = c("-r", "bilinear", "-multi", "-overwrite", "-co",
    "COMPRESS=DEFLATE", "-co", "PREDICTOR=2", "-co", "NUM_THREADS=ALL_CPUS"),
  gdal_config_options = c(VSI_CACHE = "TRUE", GDAL_CACHEMAX = "30%", VSI_CACHE_SIZE =
    "10000000", GDAL_HTTP_MULTIPLEX = "YES", GDAL_INGESTED_BYTES_AT_OPEN = "32000",
    GDAL_DISABLE_READDIR_ON_OPEN = "EMPTY_DIR", GDAL_HTTP_VERSION = "2",
    GDAL_HTTP_MERGE_CONSECUTIVE_RANGES = "YES", GDAL_NUM_THREADS = "ALL_CPUS",
    GDAL_HTTP_USERAGENT = "rsi (https://permian-global-research.github.io/rsi/)"),
  ...
)

Arguments

items

A StacItemCollection object, as returned by rsi_query_api().

aoi

Either an sf(c) object outlining the area of interest to get imagery for, or a bbox image containing the bounding box of your AOI.

asset_names

The names of the assets to download. If this vector has names, then the names of the vector are assumed to be the names of assets on the STAC server, which will be renamed to the elements of the vector in the final output.

sign_function

A function that takes the output from query_function and signs the item URLs, if necessary.

merge

Logical: for each asset, should data from multiple items be merged into a single downloaded file? If TRUE, this returns a single file for each asset, which has been merged via gdalwarp. No resampling or compositing is performed, but rather each pixel uses the last data downloaded. This is fast, but precludes per-item masking and compositing. If FALSE, each asset from each item is saved as a separate file.

gdalwarp_options

Options passed to gdalwarp through the options argument of sf::gdal_utils(). The same set of options are used for all downloaded data and the final output images; this means that some common options (for instance, PREDICTOR=3) may cause errors if bands are of varying data types. The default values are provided by rsi_gdalwarp_options().

gdal_config_options

Options passed to gdalwarp through the config_options argument of sf::gdal_utils(). The default values are provided by rsi_gdal_config_options().

...

Passed to item_filter_function.

Value

A data frame where columns correspond to distinct assets, rows correspond to distinct items, and cells contain file paths to the downloaded data.

Examples

if (FALSE) { # interactive()
aoi <- sf::st_point(c(-74.912131, 44.080410))
aoi <- sf::st_set_crs(sf::st_sfc(aoi), 4326)
aoi <- sf::st_buffer(sf::st_transform(aoi, 5070), 100)

landsat_image <- get_landsat_imagery(
  aoi,
  start_date = "2022-06-01",
  end_date = "2022-08-30",
  download_function = rsi_download_rasters
)

}