dem_sky_view_factor — DEM `visibility` op

• Data kinds: depth → image2d

• Call: import fullseye as fs; fs.ledger.dem_sky_view_factor(dem, cell_size, n_azimuth=16, max_distance_m=None) (to call the implementation directly, import demops; demops.dem_sky_view_factor(dem, cell_size, n_azimuth=16, max_distance_m=None); from the registry, opsdem.get("dem_sky_view_factor"))

Usage

Sky view factor [0,1]: how much of the sky is visible.

Computed as mean(cos^2(horizon)) from the horizon elevation angles in n_azimuth directions (the standard approximation assuming a sky of isotropic luminance). Exactly 1 on a flat surface. A quantity that matters for urban heat and cold pooling in valley bottoms.

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)

• poc_dem_terrain — py -3.11 examples/poc_dem_terrain.py

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

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Same category (`visibility`)

dem_horizon_angle · dem_viewshed

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

dem_sky_view_factor — DEM visibility op