@s57-parser/s101

Experimental parser for IHO S-101 (S-100 framework) ENC datasets, with GeoJSON conversion and a mapping of S-101 feature types to S-57 object codes, so the S-52 renderer can draw them.

ESM only. Node.js 18+, Bun, browsers.

npm install @s57-parser/s101

import { isS101, parseS101, toGeoJSON } from '@s57-parser/s101';

if (isS101(buffer)) {
  const ds = parseS101(buffer);
  ds.features[0].featureTypeName; // e.g. 'Light'
  const geojson = toGeoJSON(ds);
  // properties: featureType, featureTypeCode, OBJL (S-57 code when mapped),
  // ATTL_<code>, CATF_<code> (complex attributes), _featureAssociations
}

isS101() returns false for S-57 cells (their DSID carries STED/EXPP) and for data that is not ISO 8211, so it is safe for format detection.

Status

The parser reads S-57-style record fields (FRID with NFTC, ATTF, NATF, CATF, FSPT, FFAS, FIAS, IRID, VRID/SG2D/SG3D/VRPT/CCOC). It is tested against synthetic datasets only. Real S-101 cells encoded per S-100 Part 10a (ATTR, SPAS, C2IT/C2IL, PRID/CRID/SRID, ...) are not supported yet. Treat the API as unstable.

API

• parseS101(buffer), isS101(buffer), toGeoJSON(dataset, featureTypeCodes?), spatialKey()
• S101_FEATURE_CATALOGUE (code → name), S101_FEATURE_BY_NAME, S101_TO_S57_OBJL
• S101Primitive, S101SpatialType, CurveType and the dataset types

Part of s57-parser. MIT licence.