Terrain Map View
- Author: Copyrights (c) 2014 by Volker Wichmann
- Menu: Visualization | Grid
Description
This tool allows one to create different terrain visualisations from an elevation dataset:
* Topography: a simple map with an analytical hillshading of the terrain
* Morphology: a map which visualizes the terrain by combining positive and negative openness (Yokoyama et al. 2002) with terrain slope in a single map. In contrast to conventional shading methods this has the advantage of being independent from the direction of the light source.
References:
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.
Parameters
| | Name | Type | Identifier | Description | Constraints |
|---|
| Input | DEM | grid, input | DEM | Digital elevation model. | - |
| Output | Shade | grid, output, optional | SHADE | The shaded DTM. | - |
| Openness | grid, output, optional | OPENNESS | The difference of positive and negative openness. | - |
| Slope | grid, output, optional | SLOPE | The calculated terrain slope [radians]. | - |
| Contours | shapes, output, optional | CONTOURS | The generated contour lines. | - |
| Options | Grid System | grid system | PARAMETERS_GRID_SYSTEM | - | - |
| Method | choice | METHOD | Choose the map type to generate. | Available Choices:
[0] Topography
[1] Morphology
Default: 0 |
| Radial Limit | floating point number | RADIUS | Radial search limit for openness calculation. | Minimum: 0.000000
Default: 1000.000000 |
| Contour Lines | boolean | CONTOUR_LINES | Derive contour lines. | Default: 1 |
| Equidistance | floating point number | EQUIDISTANCE | Contour lines equidistance [map units]. | Minimum: 0.000000
Default: 50.000000 |
Command Line
Usage: saga_cmd grid_visualisation 8 [-DEM ] [-SHADE ] [-OPENNESS ] [-SLOPE ] [-CONTOURS ] [-METHOD ] [-RADIUS ] [-CONTOUR_LINES ] [-EQUIDISTANCE ]
-DEM: DEM
grid, input
-SHADE: Shade
grid, output, optional
-OPENNESS: Openness
grid, output, optional
-SLOPE: Slope
grid, output, optional
-CONTOURS: Contours
shapes, output, optional
-METHOD: Method
choice
Available Choices:
[0] Topography
[1] Morphology
Default: 0
-RADIUS: Radial Limit
floating point number
Minimum: 0.000000
Default: 1000.000000
-CONTOUR_LINES: Contour Lines
boolean
Default: 1
-EQUIDISTANCE: Equidistance
floating point number
Minimum: 0.000000
Default: 50.000000