{
  "crs": "EPSG:4326 WGS84 source",
  "projection": "local equirectangular tangent approximation",
  "origin_lonlat": [
    116.30579,
    39.99264
  ],
  "earth_radius_m": 6378137.0,
  "axes": "X east, Y north, Z up",
  "unit": "metre",
  "accuracy": "OSM map geometry, not architectural survey; height/width attributes may be inferred"
}