RSAGA (version 1.4.0)

rsaga.hillshade: Analytical hillshading Analytical hillshading calculation.

Description

Analytical hillshading Analytical hillshading calculation.

Usage

rsaga.hillshade(
  in.dem,
  out.grid,
  method = "standard",
  azimuth = 315,
  declination = 45,
  exaggeration = 4,
  ...
)

Value

The type of object returned depends on the intern argument passed to the rsaga.geoprocessor(). For intern=FALSE it is a numerical error code (0: success), or otherwise (default) a character vector with the module's console output.

Arguments

in.dem

Input digital elevation model (DEM) as SAGA grid file (default extension: .sgrd).

out.grid

Output hillshading grid (SAGA grid file). Existing files will be overwritten!

method

Available choices (character or numeric): "standard" (or 0 - default), "max90deg.standard" (1), "combined.shading" (2), "ray.tracing" (3). See Details.

azimuth

Direction of the light source, measured in degree clockwise from the north direction; default 315, i.e. northwest.

declination

Declination of the light source, measured in degree above the horizon (default 45).

exaggeration

Vertical exaggeration of elevation (default: 4). The terrain exaggeration factor allows to increase the shading contrasts in flat areas.

...

Optional arguments to be passed to rsaga.geoprocessor(), including the env RSAGA geoprocessing environment.

Author

Alexander Brenning (R interface), Olaf Conrad (SAGA module)

Details

The Analytical Hillshading algorithm is based on the angle between the surface and the incoming light beams, measured in radians.

See Also

rsaga.solar.radiation(), rsaga.insolation()

Examples

if (FALSE) rsaga.hillshade("dem.sgrd","hillshade")