dem_roughness — DEM surface op

• Data kinds: depth → image2d

• Call: import fullseye as fs; fs.ledger.dem_roughness(dem, cell_size=1.0) (to call the implementation directly, import demops; demops.dem_roughness(dem, cell_size=1.0); from the registry, opsdem.get("dem_roughness"))

Usage

Terrain ruggedness index TRI — the root mean square of the elevation differences to the 8 neighbors [m].

Riley et al. (1999). cell_size does not affect the result, but it is accepted (and validated) to make the caller aware that the unit is m.

Detailed usage guide

• dem_terrain_analysis family guide

References (sample data, literature)

• Sample-data catalog (download URLs / licences) — 2-D uses skimage.data (BSD/public domain) plus synthetic images; 3-D lists download URLs for real data sources (Stanford, PDS, …).

• Operator provenance and references — the sources of the research/methods this op family came from.

• The canonical algorithm (author, year) and its uses are named in the family usage guide above.

Runnable examples (verified samples that actually call this op)

• dem_terrain_analysis_tour — py -3.11 examples/dem_terrain_analysis_tour.py

Ops the type connects to (they accept image2d as input)

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Same category (surface)

dem_slope · dem_aspect · dem_curvature · dem_tpi

*Provenance: demops.py — DEM operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.