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get Digital Earth Africa L8/L9 GEOMAD with {vrtility}
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# how to get at Digital Eath Africa GeoMAD datasets | |
library(vrtility) | |
mirai::daemons(10) | |
bbox <- gdalraster::bbox_from_wkt( | |
wkt = "POINT (46.33 -15.9)", | |
extend_x = 0.15, | |
extend_y = 0.2 | |
) | |
l8l9_query <- stac_query( | |
bbox = bbox, | |
stac_source = "https://explorer.digitalearth.africa/stac/", | |
collection = "gm_ls8_ls9_annual", | |
start_date = "2024-01-01", | |
end_date = "2024-12-31" | |
) | |
# if you only want selected bands you can filter the assets. | |
# l8l9_query_rgb <- rstac::assets_select( | |
# l8l9_query, | |
# asset_names = c("SR_B2", "SR_B3", "SR_B4") | |
# ) | |
# Doing this once saves you having to add it to every vrt_x command. | |
Sys.setenv( | |
AWS_NO_SIGN_REQUEST = "YES", | |
AWS_S3_ENDPOINT = "s3.af-south-1.amazonaws.com" | |
) | |
l8l9_vrt <- vrt_collect( | |
l8l9_query | |
) | |
# if you just want to look at one of the tiles... | |
# plot(l8l9_vrt[[1]][[2]], c(3, 2, 1)) | |
bbox_proj <- bbox_to_projected(bbox, l8l9_vrt$srs) | |
l8l9_vrt_warped <- vrt_warp( | |
l8l9_vrt, | |
t_srs = attr(bbox_proj, "wkt"), | |
te = bbox_proj, | |
tr = c(30, 30) | |
) |> | |
vrt_stack() | |
l8l9file <- vrt_compute( | |
l8l9_vrt_warped, | |
outfile = fs::file_temp(ext = "tif"), | |
engine = "gdalraster" | |
) | |
plot_raster_src( | |
l8l9file, | |
bands = c(3, 2, 1) | |
) |
Author
h-a-graham
commented
Jul 3, 2025
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