In CRAN or offline builds, network-dependent chunks are not evaluated.
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 | Main function | Shows | Output type |
|---|---|---|---|
| Discover tiles and coverage | bluertopo_tiles() | AOI intersection, selected footprints, coverage diagnostics | Tables and footprint figure |
| Download original assets | bluertopo_download() | Verified NOAA GeoTIFF and RAT sidecar assets | Manifest tables and status figure |
| Extract elevation with terra | bluertopo() | File-backed terra object and provenance | terra summary tables and raster figure |
| Compare resolution policies | bluertopo_tiles() | Native source-resolution selection effects | Policy comparison tables and maps |
| Mixed grids and output grid | bluertopo() | SpatRasterCollection versus explicit output grid | Grid summary tables and raster figure |
| Layers and RAT metadata | bluertopo() | Elevation, uncertainty, contributor IDs, and RAT metadata | Layer/RAT tables and raster figures |
resolution selects native source tiles.
output_resolution is used only when the user explicitly
requests an output grid.