cded {bcmaps}

Canadian Digital Elevation Model (CDED)

Description

Digital Elevation Model (DEM) for British Columbia produced by GeoBC. This data is the TRIM DEM converted to the Canadian Digital Elevation Data (CDED) format. The data consists of an ordered array of ground or reflective surface elevations, recorded in metres, at regularly spaced intervals. The spacing of the grid points is .75 arc seconds north/south. The data was converted into 1:50,000 grids for distribution. The scale of this modified data is 1:250,000 which was captured from the original source data which was at a scale of 1:20,000.

Usage

cded(
  aoi = NULL,
  tiles_50K = NULL,
  .predicate = sf::st_intersects,
  dest_vrt = tempfile(fileext = ".vrt"),
  ask = interactive(),
  check_tiles = TRUE
)

Arguments

aoi

Area of Interest. Currently supports sf and sp polygons, stars and raster objects.

tiles_50K

a character vector of 1:50,000 NTS mapsheet tiles

.predicate

geometry predicate function used to find the mapsheets from your aoi. Default sf::st_intersects.

dest_vrt

The location of the vrt file. Defaults to a temporary file, but can be overridden if you'd like to save it for a project

ask

Should the function ask the user before downloading the data to a cache? Defaults to the value of interactive().

check_tiles

Should the tiles that you already have in your cache be checked to see if they need updating? Default TRUE. If you are running the same code frequently and are confident the tiles haven't changed, setting this to FALSE will speed things up.

Value

path to a .vrt file of the cded tiles for the specified area of interest

Examples

## Not run: 
vic <- census_subdivision()[census_subdivision()$CENSUS_SUBDIVISION_NAME == "Victoria", ]
vic_cded <- cded(aoi = vic)

## End(Not run)