Questions tagged [tpi]

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Stripes in TPI from SRTM 30 DEM

The TPI is calculated with a 150 to 300m annulus in Google Earth Engine. The underlying Elevation-Data from SRTM does not show such striped. I did use raw SRTM from GEE for elevation, no reprojecting ...
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156 views

Using SAGA GIS for TPI classification?

I processed one country with TPI, and I got a certain Landforms classification of terrain. (Topographic Position Index (TPI) calculation as proposed by Guisan et al. (1999)). When I processed only one ...
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103 views

ee.Image.focal_mean() unwantedly smothes the pixels Google Earth Engine

I need the focal mean of Each Pixel neighborhood for a calculation of Topographic position Index applying the ee.Image.focal_mean() to an elevation Model yields a smoothed grid. e.g its pixel size is ...
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1answer
36 views

How to merge pixel values to the nearest maximum value based on area in a classified raster?

We have a raster image with 9 discrete values. Generated the image using SAGA's Terrain Analysis -> Morphometry -> TPI classification technique. Now, like to merge pixels which occupy certain area (...
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3answers
1k views

How to conduct logistic regression between two rasters

I have two rasters. The first raster is a region showing sinkholes(depressions) of the region(cell values are 1 for sinkholes and 0 for non-sinkhole cells). The second raster is the TPI(Topographic ...
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320 views

Will Topographic Position Index (Tpi) not work in scattered raster layers?

I have a non-continuous elevation raster layer and want to use tpi in the spatialEco package in R. The elevation raster is in EPSG:5677 and looks like this: I always get this (to me) rather cryptic ...