sits (version 1.1.0)

sits_regularize: Build a regular data cube from an irregular one

Description

Produces regular data cubes for analysis-ready data (ARD) image collections. Analysis-ready data (ARD) collections available in AWS, MPC, USGS and DEAfrica are not regular in space and time. Bands may have different resolutions, images may not cover the entire time, and time intervals are not regular. For this reason, subsets of these collection need to be converted to regular data cubes before further processing and data analysis.

This function requires users to include the cloud band in their ARD-based data cubes.

Usage

sits_regularize(
  cube,
  period,
  res,
  roi = NULL,
  output_dir,
  multicores = 1,
  memsize = 4,
  progress = TRUE
)

Value

A sits_cube object with aggregated images.

Arguments

cube

sits_cube object whose observation period and/or spatial resolution is not constant.

period

ISO8601-compliant time period for regular data cubes, with number and unit, where "D", "M" and "Y" stand for days, month and year; e.g., "P16D" for 16 days.

res

Spatial resolution of regularized images (in meters).

roi

A named numeric vector with a region of interest. See more above.

output_dir

Valid directory for storing regularized images.

multicores

Number of cores used for regularization; used for parallel processing of input.

memsize

Memory available for regularization (in GB).

progress

show progress bar?

References

Appel, Marius; Pebesma, Edzer. On-demand processing of data cubes from satellite image collections with the gdalcubes library. Data, v. 4, n. 3, p. 92, 2019. DOI: 10.3390/data4030092.

Examples

if (sits_run_examples()) {
    # define a non-regular Sentinel-2 cube in AWS
    s2_cube_open <- sits_cube(
        source = "AWS",
        collection = "SENTINEL-S2-L2A-COGS",
        tiles = c("20LKP", "20LLP"),
        bands = c("B8A", "SCL"),
        start_date = "2018-10-01",
        end_date = "2018-11-01"
    )
    # create a directory to store the regularized images
    dir_images <- paste0(".", "/images_regcube/")
    if (!dir.exists(dir_images)) {
        dir.create(dir_images)
    }
    # regularize the cube
    rg_cube <- sits_regularize(
        cube = s2_cube_open,
        output_dir = dir_images,
        res = 60,
        period = "P16D",
        multicores = 2,
        memsize = 16
    )
}