PostGIS

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.

Availability: 2.1.0

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