Download original assets

This example uses BlueTopo source tiles from the National Bathymetric Source catalog. The build verifies the downloaded assets and records their source metadata.

This example uses BlueTopo tiles covering New York Harbor. The workflow demonstrates tile discovery, checksum-verified asset retrieval, and file-backed raster access with terra. Raster Attribute Table (RAT) sidecars are retained with the source GeoTIFF assets.

Example area

First download

manifest <- bluertopo_download(
  real_aoi,
  path = real$download_dir,
  resolution = "native",
  coverage = "fill",
  rat = TRUE,
  verify = "sha256",
  on_exists = "verify",
  progress = FALSE,
  quiet = TRUE
)

Tile ID	Asset	Source file	Status	Verification	Verified	Size (MB)	SHA-256	Attempts
BH4XC5FK	GeoTIFF	BlueTopo_BH4XC5FK_20260624.tiff	Reused and verified	sha256	Yes	5.393	878be33a85f5	0
BH4XC5FK	RAT	BlueTopo_BH4XC5FK_20260624.tiff.aux.xml	Reused and verified	sha256	Yes	0.104	21405b45e162	0
BH4XD5FK	GeoTIFF	BlueTopo_BH4XD5FK_20260624.tiff	Reused and verified	sha256	Yes	4.093	35174b851869	0
BH4XD5FK	RAT	BlueTopo_BH4XD5FK_20260624.tiff.aux.xml	Reused and verified	sha256	Yes	0.067	59814a3e330c	0

Reuse existing verified files

Status	count	verified_count
Reused and verified	4	4

Manifest files

Manifest file	Exists	Bytes
bluertopo-pkgdown-real-examples/downloads/new-york-harbor-upper-bay-2026-07-10/bluertopo-download-manifest.csv	Yes	2441
bluertopo-pkgdown-real-examples/downloads/new-york-harbor-upper-bay-2026-07-10/bluertopo-download-manifest.json	Yes	6655
downloads/new-york-harbor-upper-bay-2026-07-10/manifests/bluertopo-download-manifest-9d8d15e960090e3c.csv	Yes	2441
downloads/new-york-harbor-upper-bay-2026-07-10/manifests/bluertopo-download-manifest-9d8d15e960090e3c.json	Yes	6655

Source domain summary

domain	Asset	Freq

Download status counts

SHA-256 verified download status counts for the selected BlueTopo assets.

The second call reports reused_verified for files that already exist and still match NOAA SHA-256 checksums. RAT sidecars are downloaded and verified with the GeoTIFF assets.