reproject_gebco: Reproject a GEBCO raster to bathymetry, slope, and aspect...

In afsc-gap-products/akgfmaps: Alaska Groundfish and Ecosystem Survey Area Mapping

Reproject a GEBCO raster to bathymetry, slope, and aspect rasters

Description

Reprojects GEBCO raster to a new extent, resolution, and coordinate reference system. Option to also calculate slope and aspect from the rasters.

Usage

reproject_gebco(
  x,
  z_varname = "elevation",
  z_direction = -1,
  raster_template = NULL,
  extent = NULL,
  resolution = NULL,
  set_crs = NULL,
  return_slope_aspect = FALSE,
  interpolation_method = "bilinear",
  slope_nn = 8,
  slope_units = "degrees"
)

Arguments

x	Either a filepath to a GEBCO netCDF bathymetry file or a raster object.
z_varname	Name of the variable name for elevation/depth in the GEBCO raster.
z_direction	Direction for depth (negative one if positive depth is down)
raster_template	A terra SpatRaster that is used as the template for projecting the gebco_raster. In other words, the GEBCO bathymetry will be projected to the extent, resolution, and coordinate reference system of raster_template. Must provide raster_template OR extent, resolution, and CRS.
extent	Extent of for a raster_template as an sf object or 4L named numeric vector with names xmin, xmax, ymin, ymax (e.g. extent = c(xmn = -2075672, xmx = -149672.2, ymn = 427321.3, ymx = 2027321)). Must be provided if raster_template is not provided.
resolution	Resolution for a raster_template as a 2L numeric vector where values denote the x and y grid cell resolution. Must be provided if raster_template is not provided
set_crs	Coordinate reference system for the output. Uses the same crs as raster_template if not provided; must be provided if raster_template argument is not provided.
return_slope_aspect	Logical. Should slope and aspect also be returned in the output?
interpolation_method	Method for interpolating raster during reprojection.
slope_nn	Number of nearest neighbor cells to use for calculating slope (must be 4 or 8).
slope_units	Character vector denoting units for slope and aspect ("degrees" or "radians").

Value

A rasterLayer object with bathymetry when return_slope_aspect argument is FALSE. If return_slope_argument is TRUE, returns a rasterLayer with seafloor_bathymetry, slope, and aspect.

afsc-gap-products/akgfmaps documentation built on April 14, 2025, 7:13 p.m.