greenSD (version 0.1.1)

get_s2a_ndvi: Retrieve Sentinel-2-l2a images to compute NDVI

Description

download Sentinel-2-l2a imagery data and compute NDVI. Users can define an area of interest using a bounding box or place name.

Usage

get_s2a_ndvi(
  bbox = NULL,
  place = NULL,
  datetime = c(),
  cloud_cover = 10,
  vege_perc = 0,
  select = "latest",
  method = "first",
  mask = TRUE,
  output_bands = NULL,
  quiet = TRUE
)

Value

A SpatRaster object containing (multiple) NDVI layer(s) (for different period of time) select = "latest" or select = "first"

(or if mask = TRUE and select = "all")

A List of NDVI rasters if mask = FALSE and select = "all".

Arguments

bbox

sf, sfc, or a numeric vector (xmin, ymin, xmax, ymax) defining the area of interest. Optional if place is provided.

place

character or vector. (optional) A single line address, e.g. ("1600 Pennsylvania Ave NW, Washington") or a vector of addresses (c("Madrid", "Barcelona")).

datetime

numeric vector of 2. The time of interest such as c("2020-08-01", "2020-09-01").

cloud_cover

numeric. Threshold for the percentage of cloud coverage. Desfault is 10.

vege_perc

numeric. Threshold for the percentage of vegetation coverage. Desfault is 0.

select

character. one of "latest", "earliest", "all". The default is "latest".

method

character. A method for mosaicing layers: one of "mean", "median", "min", "max", "modal", "sum", "first", "last". The default is "first".

mask

logical (optional). Default is TRUE. If TRUE, masks the raster data using the given bbox or place.

output_bands

vector. A list of band names (c('B04', 'B08')). The default is NULL. If output_bands is specified, NDVI will not be computed and only the specified bands will be returned. All available bands can be found here

quiet

logical. Whether show progress bars for some process.

Examples

result <- get_s2a_ndvi(
  # place = 'New York',
  datetime = c("2020-08-01", "2020-09-01")
)