Topography data — readtopo • raadtools

Functions to provide topographic (bathymetry and/or topography) data.

readtopo(
  topo = c("gebco_08", "ibcso", "etopo1", "etopo2", "kerguelen", "smith_sandwell",
    "gebco_14", "macrie1100m", "macrie2100m", "cryosat2", "lake_superior", "ramp",
    "ibcso_is", "ibcso_bed", "rema_1km", "rema_200m", "rema_100m", "rema_8m", "gebco_19",
    "gebco_21"),
  polar = FALSE,
  lon180 = TRUE,
  xylim = NULL,
  returnfiles = FALSE,
  ...,
  resample = "bilinear"
)

readbathy(
  topo = c("gebco_08", "ibcso", "etopo1", "etopo2", "kerguelen", "smith_sandwell",
    "gebco_14", "macrie1100m", "macrie2100m", "cryosat2", "lake_superior", "ramp",
    "ibcso_is", "ibcso_bed", "rema_1km", "rema_200m", "rema_100m", "rema_8m", "gebco_19",
    "gebco_21"),
  polar = FALSE,
  lon180 = TRUE,
  xylim = NULL,
  returnfiles = FALSE,
  ...,
  resample = "bilinear"
)

topofile(
  topo = c("gebco_08", "ibcso", "etopo1", "etopo2", "kerguelen", "smith_sandwell",
    "gebco_14", "macrie1100m", "macrie2100m", "cryosat2", "lake_superior", "ramp",
    "ibcso_is", "ibcso_bed", "rema_1km", "rema_200m", "rema_100m", "rema_8m", "gebco_19",
    "gebco_21"),
  polar = FALSE,
  lon180 = TRUE,
  ...
)

read_rema_tiles(...)

Arguments

topo: Data source, see Details.
polar: Flag for returning the polar version of the IBCSO data.
lon180: Flag for returning data in Atlantic -180, 180 rather than Pacific 0, 360 view.
xylim: spatial extents or raster grid to crop from source data, see Details
returnfiles: Return just the relevant file name
...: reserved for future use, ignored currently
resample: method to use for GDAL warper resampling (currently via terra), the 'method' argument to 'project()'

Value

: topofile returns a character string of the full path to a file name
: readtopo and readbathy return the requested data as a RasterLayer (these are aliases)

Details

Use readtopo (or its alias readbathy) to read data from the chosen data set. The function topofile is used to find the full file name.

readtopo() and readbathy() accept terra::ext or raster::extent or just numeric objects for 'xylim'. Alternatively these can be a terra SpatRaster or a raster BasicRaster (RasterLayer, RasterBrick, or RasterStack) as a template target raster for crop and resize, or reprojection to new raster grid. The 'resample' argument controls the kind of sampling when regridded or warped. (i.e. if xylim is extent, you get crop(), if it's a grid, it is remodelled to the grid. extent doesn't need crs, grid does). The following data sets are available using the argument topo.

gebco_08: The GEBCO_08 Grid, a global 30 arc-second grid largely generated by combining quality-controlled ship depth soundings with interpolation between sounding points guided by satellite-derived gravity data. http://www.gebco.net/data_and_products/gridded_bathymetry_data/
ibcso: IBCSO bathymetry data, resolution 1min, use argument polar = TRUE to return the projected version (polar stereographic with true scale at 71S, WGS84), 500m resolution. http://www.ibcso.org/data.html. Default is Ice Surface 'ibcso_is', use 'ibcso_bed' for Bedrock.
etopo1: ETOPO1 is a 1 arc-minute global relief model of Earth's surface that integrates land topography and ocean bathymetry. http://www.ngdc.noaa.gov/mgg/global/global.html
etopo2: Historic and deprecated prior version of ETOPO1. http://www.ngdc.noaa.gov/mgg/global/etopo2.html
kerguelen: Kerguelen Plateau Bathymetric Grid, https://data.gov.au/dataset/ds-ga-a05f7893-007f-7506-e044-00144fdd4fa6/details?q=
george_v_terre_adelie: A bathymetric Digital Elevation Model (DEM) of the George V and Terre Adelie continental shelf and margin - 100, 250, and 500 metre resolution. http://data.aad.gov.au/aadc/metadata/metadata_redirect.cfm?md=AMD/AU/GVdem_2008
smith_sandwell: Global seafloor topography from satellite altimetry and ship depth soundings. http://topex.ucsd.edu/WWW_html/mar_topo.html
cryosat2: Antarctica CryoSat-2 Digital Elevation Model (DEM). https://earth.esa.int/web/guest/missions/esa-operational-eo-missions/cryosat
lake_superior: Bathymetry of Lake Superior https://www.ngdc.noaa.gov/mgg/greatlakes/superior.html
ramp: Radarsat Antarctic digital elevation model V2 https://github.com/AustralianAntarcticDivision/blueant#radarsat-antarctic-digital-elevation-model-v2
ga_srtm: Digital Elevation Model (DEM) of Australia with 1 Second Grid
rema_1km, rema_200m, rema_100m, rema_8m: Reference Elevation Model of Antartica (REMA) for the peninsula, see read_rema_tiles for the index
gebco_19: GEBCO_2019 Grid https://www.gebco.net/data_and_products/gridded_bathymetry_data/gebco_2019/gebco_2019_info.html