poka.sh

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DEM

Generated by scripts/gen-format-pages.py from docs/data/format-metadata/, FILE_FORMATS.csv and docs/formats-master.csv. Do not edit by hand: change the source, then run the script.

Elevation DEM Preview.

At a glance
Purpose A USGS Standard DEM: a digital elevation model with an A record of metadata and B records of elevation profiles.
Extensions .dem
Poka parser poka-dem
Viewer poka-3d-viewer
Depth tier Parser with a shared viewer (see Depth tiers)
Breadth tier B2 Broad (see Breadth tiers)

How much Poka reads

B2 Broad. The common content of the current and the common older versions is decoded. Some named features or versions are not, and are listed.

Confidence: high (the reviewer read the code and a test that proves the claim). Basis: Reviewed 2026-10-26: read parsers/poka-dem/src/main.rs (797 lines) and plugin.json. 15 unit tests (Fortran D exponents, fixed and per-line records, arc-second spacing, units, truncation, voids) and corpus_dems_state_metre_elevations over the corpus elevation.dem. Covers .dem and .dted. The A record's scale and units and every B profile are read as a number stream, placed by their first northing with the local datum added, voids left open, and drawn as a terrain mesh; large sheets are thinned to every n-th post rather than cropped. Judgement: B2: the elevations are read and drawn in full; the gaps are metadata and DTED.

What Poka does not read

  • A-record metadata (quadrangle name, projection, corners) is used, not shown (judgement from the code)
  • The C record (accuracy) is not read
  • Large sheets are thinned to every n-th post
  • DTED files (.dted) are a different format and are refused, although the extension is routed here (judgement from the code)

Libraries

Libraries Poka uses or has assessed for this format, with the status, licence and language the registry records.

Sources

  • parsers/poka-dem/src/main.rs
  • parsers/poka-dem/plugin.json