SAGA-GIS Tool Library Documentation (v8.1.0)

Tool Topographic Openness

Topographic openness expresses the dominance (positive) or enclosure (negative) of a landscape location. See Yokoyama et al. (2002) for a precise definition. Openness has been related to how wide a landscape can be viewed from any position. It has been proven to be a meaningful input for computer aided geomorphological mapping.


References


Parameters

 NameTypeIdentifierDescriptionConstraints
InputElevationGrid, inputDEM--
OutputPositive OpennessGrid, outputPOS--
Negative OpennessGrid, outputNEG--
OptionsGrid SystemGrid systemPARAMETERS_GRID_SYSTEM--
Radial LimitFloating pointRADIUSMaximum search distance [map units].Minimum: 0.000000
Default: 10000.000000
DirectionsChoiceDIRECTIONS-Available Choices:
[0] single
[1] all
Default: 1
DirectionFloating pointDIRECTIONSingle direction given as degree measured clockwise from the North direction.Minimum: -360.000000
Maximum: 360.000000
Default: 315.000000
Number of SectorsIntegerNDIRS-Minimum: 4
Default: 8
MethodChoiceMETHOD-Available Choices:
[0] multi scale
[1] line tracing
Default: 1
Multi Scale FactorFloating pointDLEVEL-Minimum: 1.250000
Default: 3.000000
UnitChoiceUNIT-Available Choices:
[0] Radians
[1] Degree
Default: 0
Difference from NadirBooleanNADIRIf set, output angles are the mean difference from nadir, or else from a plane.Default: 1

Command-line

Usage: saga_cmd ta_lighting 5 [-DEM <str>] [-POS <str>] [-NEG <str>] [-RADIUS <double>] [-DIRECTIONS <str>] [-DIRECTION <double>] [-NDIRS <num>] [-METHOD <str>] [-DLEVEL <double>] [-UNIT <str>] [-NADIR <str>]
  -DEM:<str>         	Elevation
	Grid, input
  -POS:<str>         	Positive Openness
	Grid, output
  -NEG:<str>         	Negative Openness
	Grid, output
  -RADIUS:<double>   	Radial Limit
	Floating point
	Minimum: 0.000000
	Default: 10000.000000
  -DIRECTIONS:<str>  	Directions
	Choice
	Available Choices:
	[0] single
	[1] all
	Default: 1
  -DIRECTION:<double>	Direction
	Floating point
	Minimum: -360.000000
	Maximum: 360.000000
	Default: 315.000000
  -NDIRS:<num>       	Number of Sectors
	Integer
	Minimum: 4
	Default: 8
  -METHOD:<str>      	Method
	Choice
	Available Choices:
	[0] multi scale
	[1] line tracing
	Default: 1
  -DLEVEL:<double>   	Multi Scale Factor
	Floating point
	Minimum: 1.250000
	Default: 3.000000
  -UNIT:<str>        	Unit
	Choice
	Available Choices:
	[0] Radians
	[1] Degree
	Default: 0
  -NADIR:<str>       	Difference from Nadir
	Boolean
	Default: 1