sits_regularize {sits}R Documentation

Creates a regularized data cube from an irregular one

Description

Creates cubes with regular time intervals using the gdalcubes package. Cubes can be composed using "min", "max", "mean", "median" or "first" functions. Users need to provide an time interval which is used by the composition function.

Usage

sits_regularize(
  cube,
  output_dir,
  period = NULL,
  res = NULL,
  roi = NULL,
  agg_method = "median",
  resampling = "bilinear",
  cloud_mask = TRUE,
  multicores = 1
)

Arguments

cube

A sits_cube object whose spacing of observation times is not constant and will be regularized by the gdalcubes package.

output_dir

A character with a valid directory where the regularized images will be written by gdalcubes.

period

A character with ISO8601 time period for regular data cubes produced by gdalcubes, with number and unit, e.g., "P16D" for 16 days. Use "D", "M" and "Y" for days, month and year.

res

A numeric with spatial resolution of the image that will be aggregated.

roi

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

agg_method

A character with method that will be applied by gdalcubes for aggregation. Options: min, max, mean, median and first.

resampling

A character with method to be used by gdalcubes for resampling in mosaic operation. Options: near, bilinear, bicubic or others supported by gdalwarp (see https://gdal.org/programs/gdalwarp.html). By default is bilinear.

cloud_mask

A logical to use cloud band for aggregation by gdalcubes. Default is TRUE.

multicores

A numeric with the number of cores will be used in the regularize. By default is used 1 core.

Value

A sits_cube object with aggregated images.

Note

The "roi" parameter defines a region of interest. It can be an sf_object, a shapefile, or a bounding box vector with named XY values ("xmin", "xmax", "ymin", "ymax") or named lat/long values ("lat_min", "lat_max", "long_min", "long_max")

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

{
## Not run: 

# --- Access to the AWS STAC
# Provide your AWS credentials as environment variables
Sys.setenv(
    "AWS_ACCESS_KEY_ID" = <your_aws_access_key>,
    "AWS_SECRET_ACCESS_KEY" = <your_aws_secret_access_key>
)

# define an AWS data cube
  s2_cube <- sits_cube(source = "AWS",
                      name = "T20LKP_2018_2019",
                      collection = "sentinel-s2-l2a-cogs",
                      bands = c("B08", "SCL"),
                      tiles = c("20LKP"),
                      start_date = as.Date("2018-07-18"),
                      end_date = as.Date("2018-08-18")
  )

# create a directory to store the resulting images
dir.create(paste0(tempdir(),"/images/"))

# Build a data cube of equal intervals using the "gdalcubes" package
gc_cube <- sits_regularize(cube       = s2_cube,
                           output_dir = paste0(tempdir(),"/images/"),
                           period     = "P1M",
                           agg_method = "median",
                           resampling = "bilinear",
                           cloud_mask = TRUE)

## End(Not run)
}


[Package sits version 0.15.0 Index]