Tool NameTPI Based Landform Classification
Tool ID19
Library IDta_morphometry
Version1.0
Author(s)O.Conrad (c) 2011

Please cite SAGA whenever you use it for your publications:

doi:10.5194/gmd-8-1991-2015

Description

Topographic Position Index (TPI) calculation as proposed by Guisan et al. (1999). This is literally the same as the difference to the mean calculation (residual analysis) proposed by Wilson & Gallant (2000). The bandwidth parameter for distance weighting is given as percentage of the (outer) radius.

Parameters

NameTypeIdentifierDescriptionConstraints
Input
Elevationgrid, inputDEM
Output
Landformsgrid, outputLANDFORMS
Classestable, output, optionalCLASSES
Options
Small Scalevalue rangeRADIUS_Akernel radius; defines an annulus if minimum is greater than zeroDefault: 0; 100
Large Scalevalue rangeRADIUS_Bkernel radius; defines an annulus if minimum is greater than zeroDefault: 0; 1000
Radius UnitchoiceUNITAvailable Choices:
[0] map units
[1] cells
Default: 0
Weighting FunctionchoiceDW_WEIGHTINGAvailable Choices:
[0] no distance weighting
[1] inverse distance to a power
[2] exponential
[3] gaussian
Default: 0
Powerfloating point numberDW_IDW_POWERMinimum: 0.000000
Default: 2
Bandwidthfloating point numberDW_BANDWIDTHBandwidth for exponential and Gaussian weightingMinimum: 0.000000
Default: 75