Measure correlating strongly with slope 
Roughness Measure MICRODEM, Create derivative grid GRASS (callable from Windows command line) SAGA GDAL (callable from Windows command line) WhiteBox (callable from Windows command line) Reference
SSR           Sebastiano Trevisani, Giordano Teza, & Peter L. Guth. (2023). Hacking the topographic ruggedness index.
Roughness factor Byproduct of SSO computations     GDAL Roughness is the largest inter-cell difference of a central pixel and its surrounding cells, as defined in Wilson et al (2007, Marine Geodesy 30:3-35).   Mark, 1975; Etzelmuller, 2000.
TPI Option to normalize all distances Includes multidimensional (addon,  called from MICRODEM)   Yes (does not agree with MICRODEM)   Guisan, A., S. B. Weiss, A. D. Weiss 1999. GLM versus CCA spatial modeling of plant species distribution. Plant Ecology 143: 107-122

Comparison of TRI with Various Programs
Option to normalize all distances Allows neighborhood, distance weighting  (addon,  called from MICRODEM)   Yes   Riley, S. J., S. D. DeGloria and R. Elliot (1999). A terrain ruggedness index that quantifies topographic heterogeneity, Intermountain Journal of Sciences, vol. 5, No. 1-4, pp.23-27.
Wilson et al (2007, Marine Geodesy 30:3-35)
Multiscale roughness         Yes  
MAD--median absolute differences           S. Trevisani, M. Rocca,2015, MAD: robust image texture analysis for applications in high resolution geomorphometry: Computers & Geosciences, Volume 81, pages 78-92,
Standard deviation of slope Yes         C. H. Grohmann, M. J. Smith and C. Riccomini, "Multiscale Analysis of Topographic Surface Roughness in the Midland Valley, Scotland," in IEEE Transactions on Geoscience and Remote Sensing, vol. 49, no. 4, pp. 1200-1213, April 2011, doi: 10.1109/TGRS.2010.2053546 .
Variogram gamma Yes          
Rugosity Yes
Vector ruggedness   r.roughness.vector  (addon,  called from MICRODEM)      
Multiscale Std Dev Normals         Yes (not yet callable from MICRODEM) JB Lindsay, DR Newman, and A Francioni. 2019 Scale-Optimized Surface Roughness for Topographic Analysis. Geosciences, 9(322) doi: 10.3390/geosciences9070322.

Mark, 1975; Etzelmuller, 2000.  RoughnessFactor := 1 - sqrt(sqr(x1sq) + sqr(y1sq) + sqr(z1sq)) / NumPts;  (the three numbers are the sums of the squares of the three components (directional cosines) of the normal vector to the earth's surface) done as byproduct of SSO computations


Call routines from GRASS, GDAL, and WhiteBox from MICRODEM: Raster GIS, External tools


Last revision 2/9/2023