ST_TRI — Returns a raster with the calculated Terrain Ruggedness Index.
raster ST_TRI(raster rast, integer nband, raster customextent, text pixeltype="32BF" , boolean interpolate_nodata=FALSE
Terrain Ruggedness Index is calculated by comparing a central pixel with its neighbors, taking the absolute values of the differences, and averaging the result.
This function only supports a focalmean radius of one.
ST_MapAlgebra, ST_Roughness, ST_TPI, ST_Slope, ST_HillShade, ST_Aspect