brazil-modis-ndvi-ex.R

# remotes::install_github("OldLipe/rstac@b-0.9.1")
# remotes::install_github("appelmar/gdalcubes_R")
# remotes::install_github("r-spatial/stars")
library(tidyverse)
library(rstac)
library(gdalcubes)
library(tmap)
library(stars)
data(World) #polygons

box <- World |> filter(name == "Brazil") |> pull(geometry) |> st_bbox()

matches <-
  stac("https://planetarycomputer.microsoft.com/api/stac/v1") |>
  stac_search(collections = "modis-13Q1-061",
              datetime = "2022-01-01/2022-03-01",
              bbox = c(box)) |>
  get_request() |>
  items_fetch() |>
  items_sign(sign_fn = sign_planetary_computer())

cube <- gdalcubes::stac_image_collection(matches$features,
                                         asset_names = "250m_16_days_NDVI",
                                         duration = "start")


## let's do a 1 yr average
v <- cube_view(srs = "EPSG:4326",
               extent = list(t0 = "2022-01-01", t1 = "2022-12-01",
                             left = box[1], right = box[3],
                             top = box[4], bottom = box[2]),
               dx = 0.2, dy = 0.2, dt= "P1Y",
               aggregation = "mean", resampling = "near"
)

ndvi <- raster_cube(cube,v) |> st_as_stars() 
tm_shape(ndvi) + tm_raster()