Query a STAC API using a specific spatiotemporal area of interest

This function is the default method used to retrieve lists of items to download for all the collections and endpoints supported by rsi. It will likely work for any other STAC APIs of interest.

Usage

rsi_query_api(bbox, stac_source, collection, start_date, end_date, limit, ...)

Arguments

bbox

A bbox or sfc object, from the sf package, representing the spatial bounding box of your area of interest. This must be in EPSG:4326 coordinates (and, if this function is called from within get_stac_data(), it will be) or else it will be automatically reprojected.

stac_source

Character of length 1: the STAC URL to download imagery from.

collection

Character of length 1: the STAC collection to download images from.

start_date, end_date

Character strings of length 1 representing the boundaries of your temporal range of interest, in RFC-3339 format. Set either argument to .. to use an open interval; set start_date to NULL to not pass a temporal range of interest (which may cause errors with some APIs). If this function is called from within get_stac_data(), the inputs to start_date and end_date will have already been processed to try and force RFC-3339 compliance.

limit

an integer defining the maximum number of results to return. If not informed, it defaults to the service implementation.

...

Ignored by this function. Arguments passed to get_stac_data() via ... will be available (unchanged) in this function

Value

A StacItemCollection object.

Details

You can pass your own query functions to get_stac_data() and its variants. This is the best way to perform more complex queries, for instance if you need to provide authentication to get the list of items (not just the assets) available for your AOI, or to perform cloud filtering prior to downloading assets.

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",
  query_function = rsi_query_api
)
}