PostGIS

ST_TPI — Returns a raster with the calculated Topographic Position Index.

+raster +ST_TPI(+`raster `+rast, integer nband, raster customextent, text pixeltype="32BF" , boolean + interpolate_nodata=FALSE + );

Calculates the Topographic Position Index, which is defined as the focal mean with radius of one minus the center cell.

Availability: 2.1.0

ST_MapAlgebra (callback function version), ST_TRI, ST_Roughness, ST_Slope, ST_HillShade, ST_Aspect