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Create sits cubes from cubes in flat files in a local

Source: R/sits_cube_local.R
sits_cube.local_cube.Rd

Creates data cubes based on files on local directory. Assumes users have downloaded the data from a known cloud collection or the data has been created by sits.

Usage

# S3 method for class 'local_cube'
sits_cube(
  source,
  collection,
  ...,
  bands = NULL,
  tiles = NULL,
  start_date = NULL,
  end_date = NULL,
  data_dir,
  parse_info = c("X1", "X2", "tile", "band", "date"),
  delim = "_",
  multicores = 2L,
  progress = TRUE
)

Arguments

source

Data source: one of "AWS", "BDC", "CDSE", "DEAFRICA", "DEAUSTRALIA", "HLS", "PLANETSCOPE", "MPC", "SDC" or "USGS". This is the source from which the data has been downloaded.

collection

Image collection in data source. To find out the supported collections, use sits_list_collections()).

...

Other parameters to be passed for specific types.

bands

Spectral bands and indices to be included in the cube (optional).

tiles

Tiles from the collection to be included in the cube (see details below).

start_date, end_date

Initial and final dates to include images from the collection in the cube (optional). (Date in YYYY-MM-DD format).

data_dir

Local directory where images are stored.

parse_info

Parsing information for local files.

delim

Delimiter for parsing local files (default = "_")

multicores

Number of workers for parallel processing (integer, min = 1, max = 2048).

progress

Logical: show a progress bar?

Value

A tibble describing the contents of a data cube.

Note

To create a cube from local files, please inform:

  • source: The data provider from which the data was downloaded (e.g, "BDC", "MPC");

  • collection: The collection from which the data comes from. (e.g., "SENTINEL-2-L2A" for the Sentinel-2 MPC collection level 2A);

  • data_dir: The local directory where the image files are stored.

  • parse_info: Defines how to extract metadata from file names by specifying the order and meaning of each part, separated by the "delim" character. Default value is c("X1", "X2", "tile", "band", "date").

  • delim: The delimiter character used to separate components in the file names. Default is "_".

Please ensure that local files meet the following requirements:

  • All image files must have the same spatial resolution and projection;

  • Each file should represent a single image band for a single date;

  • File names must include information about the tile, date, and band in their names.

  • The parse_info parameter tells sits how to extract metadata from file names.

  • By default the parse_info parameter is c(satellite, sensor, tile, band, date).

Example of supported file names are:

  • "CBERS-4_WFI_022024_B13_2021-05-15.tif";

  • "SENTINEL-1_GRD_30TXL_VV_2023-03-10.tif";

  • "LANDSAT-8_OLI_198030_B04_2020-09-12.tif".

When you load a local data cube specifying the source (e.g., AWS, MPC) and collection, sits assumes that the data properties (e.g., scale factor, minimum, and maximum values) match those defined for the selected provider. If you are working with custom data from an unsupported source or data that does not follow the standard definitions of providers in sits, refer to the Technical Annex of the sits online book for guidance on handling such cases (e-sensing.github.io/sitsbook/technical-annex.html).

Examples

if (sits_run_examples()) {
    # --- Create a cube based on a local MODIS data
    # MODIS local files have names such as
    # "TERRA_MODIS_012010_NDVI_2013-09-14.jp2"
    # see the parse info parameter as an example on how to
    # decode local files
    data_dir <- system.file("extdata/raster/mod13q1", package = "sits")
    modis_cube <- sits_cube(
        source = "BDC",
        collection = "MOD13Q1-6.1",
        data_dir = data_dir,
        parse_info = c("satellite", "sensor", "tile", "band", "date")
    )
}