Layers and RAT metadata

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. It opens elevation, uncertainty, and contributor layers, then reads Raster Attribute Table (RAT) sidecars for contributor metadata. Elevation is shown with hillshade and contours; uncertainty and contributor IDs are plotted as their own source layers.

The contributor band contains IDs, not continuous values. Contributor IDs must not be averaged. RAT sidecars carry contributor metadata, and bluertopo preserves original RAT files.

all_layers <- bluertopo(
  real_aoi,
  layers = "all",
  coverage = "fill",
  details = TRUE,
  progress = FALSE,
  quiet = TRUE
)