Module 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:
Anders, N. S. / Seijmonsbergen, A. C. / Bouten, W. (2009): Multi-Scale and Object-Oriented Image Analysis of High-Res LiDAR Data for Geomorphological Mapping in Alpine Mountains. Proceedings of Geomorphometry 2009. online at geomorphometry.org.

Prima, O.D.A / Echigo, A. / Yokoyama, R. / Yoshida, T. (2006): Supervised landform classification of Northeast Honshu from DEM-derived thematic maps. Geomorphology, vol.78, pp.373-386.

Yokoyama, R. / Shirasawa, M. / Pike, R.J. (2002): Visualizing topography by openness: A new application of image processing to digital elevation models. Photogrammetric Engineering and Remote Sensing, Vol.68, pp.251-266. online at ASPRS.

• Author: O.Conrad (c) 2012
• Specification: grid
• Menu: Terrain Analysis|Lighting

Parameters

Command-line

Usage: saga_cmd ta_lighting 5 -DEM <str> [-POS <str>] [-NEG <str>] [-RADIUS <str>] [-METHOD <str>] [-DLEVEL <str>] [-NDIRS <num>]
  -DEM:<str>   	Elevation
	Grid (input)
  -POS:<str>   	Positive Openness
	Grid (output)
  -NEG:<str>   	Negative Openness
	Grid (output)
  -RADIUS:<str>	Radial Limit
	Floating point
	Minimum: 0.000000
	Default: 10000.000000
  -METHOD:<str>	Method
	Choice
	Available Choices:
	[0] multi scale
	[1] sectors
	Default: 1
  -DLEVEL:<str>	Multi Scale Factor
	Floating point
	Minimum: 1.250000
	Default: 3.000000
  -NDIRS:<num> 	Number of Sectors
	Integer
	Minimum: 2
	Default: 8