{
 "ocl_version": "0.1.0",
 "name": "Discovered lane (52.1838, -3.9553)",
 "slug": "discovered-lane-52-1838-3-9553",
 "confidence": "B",
 "reported_claims": [],
 "ladder": [
  {
   "window_m": 2.0,
   "max_gradient_pct": 30.73923079307548,
   "diagnostic": true,
   "flags": [
    "texture_excluded",
    "texture_excluded",
    "texture_excluded",
    "canopy_or_structure"
   ],
   "start_distance_m": 181.0,
   "end_distance_m": 183.0,
   "start_elevation_m": 171.57157751295867,
   "end_elevation_m": 172.18636212882018,
   "min_gradient_pct": -21.41826001366809,
   "suppressed_max_gradient_pct": 51.58363490780857,
   "suppressed_location_m": [
    712.0,
    714.0
   ]
  },
  {
   "window_m": 3.0,
   "max_gradient_pct": 27.944578947951488,
   "diagnostic": true,
   "flags": [
    "texture_excluded",
    "canopy_or_structure"
   ],
   "start_distance_m": 180.0,
   "end_distance_m": 183.0,
   "start_elevation_m": 171.34802476038163,
   "end_elevation_m": 172.18636212882018,
   "min_gradient_pct": -17.200555759982688,
   "suppressed_max_gradient_pct": 46.83144802881524,
   "suppressed_location_m": [
    711.0,
    714.0
   ]
  },
  {
   "window_m": 5.0,
   "max_gradient_pct": 23.6895608572695,
   "diagnostic": false,
   "flags": [
    "texture_excluded",
    "suppression_unstable",
    "texture_excluded",
    "texture_excluded",
    "canopy_or_structure"
   ],
   "start_distance_m": 179.0,
   "end_distance_m": 184.0,
   "start_elevation_m": 171.19738509495716,
   "end_elevation_m": 172.38186313782063,
   "min_gradient_pct": -9.504649523810826,
   "suppressed_max_gradient_pct": 37.08952439712277,
   "suppressed_location_m": [
    710.0,
    715.0
   ]
  },
  {
   "window_m": 10.0,
   "max_gradient_pct": 17.60678515621123,
   "diagnostic": false,
   "flags": [
    "structure_excluded",
    "texture_excluded",
    "texture_excluded",
    "texture_excluded"
   ],
   "start_distance_m": 574.0,
   "end_distance_m": 584.0,
   "start_elevation_m": 216.6008419385573,
   "end_elevation_m": 218.36152045417842,
   "min_gradient_pct": -8.365245862399888,
   "suppressed_max_gradient_pct": 29.426348050386082,
   "suppressed_location_m": [
    614.0,
    624.0
   ]
  },
  {
   "window_m": 20.0,
   "max_gradient_pct": 17.26650237287444,
   "diagnostic": false,
   "flags": [
    "structure_excluded",
    "texture_excluded",
    "texture_excluded"
   ],
   "start_distance_m": 409.0,
   "end_distance_m": 429.0,
   "start_elevation_m": 194.08852527285993,
   "end_elevation_m": 197.5418257474348,
   "min_gradient_pct": -7.144560996662221,
   "suppressed_max_gradient_pct": 27.00551457391981,
   "suppressed_location_m": [
    607.0,
    627.0
   ]
  },
  {
   "window_m": 25.0,
   "max_gradient_pct": 16.948790624581648,
   "diagnostic": false,
   "flags": [
    "structure_excluded",
    "texture_excluded",
    "texture_excluded"
   ],
   "start_distance_m": 410.0,
   "end_distance_m": 435.0,
   "start_elevation_m": 194.25906859031264,
   "end_elevation_m": 198.49626624645805,
   "min_gradient_pct": -6.6312108516269745,
   "suppressed_max_gradient_pct": 25.285468249552423,
   "suppressed_location_m": [
    602.0,
    627.0
   ]
  },
  {
   "window_m": 50.0,
   "max_gradient_pct": 16.0967255460709,
   "diagnostic": false,
   "flags": [
    "structure_excluded",
    "texture_excluded"
   ],
   "start_distance_m": 400.0,
   "end_distance_m": 450.0,
   "start_elevation_m": 192.7192559394061,
   "end_elevation_m": 200.76761871244156,
   "min_gradient_pct": -4.963585451507356,
   "suppressed_max_gradient_pct": 22.244983972203727,
   "suppressed_location_m": [
    594.0,
    644.0
   ]
  },
  {
   "window_m": 100.0,
   "max_gradient_pct": 14.610988246196511,
   "diagnostic": false,
   "flags": [
    "structure_excluded",
    "texture_excluded",
    "texture_excluded"
   ],
   "start_distance_m": 390.0,
   "end_distance_m": 490.0,
   "start_elevation_m": 191.29620639499166,
   "end_elevation_m": 205.90719464118817,
   "min_gradient_pct": -1.8173770503965443,
   "suppressed_max_gradient_pct": 19.095477891511337,
   "suppressed_location_m": [
    559.0,
    659.0
   ]
  }
 ],
 "shape": {
  "ascent_concentration": 0.5,
  "concentration_window_frac": 0.25,
  "longest_pitch_10pct_m": 317.0,
  "shape_class": "stepped"
 },
 "length_m": 1489.6957585238276,
 "start_elevation_m": 166.3969796307322,
 "end_elevation_m": 270.3561506937262,
 "endpoint_gain_m": 103.95917106299399,
 "overall_gradient_pct": 6.978550517322371,
 "accumulated_ascent_m": 112.89839182997312,
 "window_maxima": {
  "max_5m": {
   "gradient_pct": 23.6895608572695,
   "start_distance_m": 179.0,
   "end_distance_m": 184.0,
   "midpoint_distance_m": 181.5,
   "start_elevation_m": 171.19738509495716,
   "end_elevation_m": 172.38186313782063,
   "start_xy": [
    266201.64616962674,
    255735.99728927162
   ],
   "end_xy": [
    266206.6238646492,
    255736.46903846937
   ]
  },
  "max_10m": {
   "gradient_pct": 17.60678515621123,
   "start_distance_m": 574.0,
   "end_distance_m": 584.0,
   "midpoint_distance_m": 579.0,
   "start_elevation_m": 216.6008419385573,
   "end_elevation_m": 218.36152045417842,
   "start_xy": [
    266593.8479418403,
    255776.4593883673
   ],
   "end_xy": [
    266603.5753303613,
    255774.1403580228
   ]
  },
  "max_20m": {
   "gradient_pct": 17.26650237287444,
   "start_distance_m": 409.0,
   "end_distance_m": 429.0,
   "midpoint_distance_m": 419.0,
   "start_elevation_m": 194.08852527285993,
   "end_elevation_m": 197.5418257474348,
   "start_xy": [
    266430.44573485386,
    255759.35884211
   ],
   "end_xy": [
    266450.2771861282,
    255761.94986914986
   ]
  },
  "max_25m": {
   "gradient_pct": 16.948790624581648,
   "start_distance_m": 410.0,
   "end_distance_m": 435.0,
   "midpoint_distance_m": 422.5,
   "start_elevation_m": 194.25906859031264,
   "end_elevation_m": 198.49626624645805,
   "start_xy": [
    266431.43727577664,
    255759.48863566047
   ],
   "end_xy": [
    266456.22655686986,
    255762.72767221392
   ]
  },
  "max_50m": {
   "gradient_pct": 16.0967255460709,
   "start_distance_m": 400.0,
   "end_distance_m": 450.0,
   "midpoint_distance_m": 425.0,
   "start_elevation_m": 192.7192559394061,
   "end_elevation_m": 200.76761871244156,
   "start_xy": [
    266421.52157646057,
    255758.1929203023
   ],
   "end_xy": [
    266471.1001514491,
    255764.6708967592
   ]
  },
  "max_100m": {
   "gradient_pct": 14.610988246196511,
   "start_distance_m": 390.0,
   "end_distance_m": 490.0,
   "midpoint_distance_m": 440.0,
   "start_elevation_m": 191.29620639499166,
   "end_elevation_m": 205.90719464118817,
   "start_xy": [
    266411.5962993199,
    255756.97719016823
   ],
   "end_xy": [
    266510.76296640484,
    255769.85362731203
   ]
  }
 },
 "window_minima": {
  "min_5m": {
   "gradient_pct": -9.504649523810826,
   "start_distance_m": 152.0,
   "end_distance_m": 157.0,
   "midpoint_distance_m": 154.5,
   "start_elevation_m": 171.44660453087766,
   "end_elevation_m": 170.97137205468712,
   "start_xy": [
    266174.76649993187,
    255733.45107529478
   ],
   "end_xy": [
    266179.7442450429,
    255733.92229646494
   ]
  },
  "min_10m": {
   "gradient_pct": -8.365245862399888,
   "start_distance_m": 1309.0,
   "end_distance_m": 1319.0,
   "midpoint_distance_m": 1314.0,
   "start_elevation_m": 260.1220085029091,
   "end_elevation_m": 259.28548391666914,
   "start_xy": [
    267178.94714851555,
    256102.5508035815
   ],
   "end_xy": [
    267186.616887747,
    256108.9675853111
   ]
  },
  "min_20m": {
   "gradient_pct": -7.144560996662221,
   "start_distance_m": 1304.0,
   "end_distance_m": 1324.0,
   "midpoint_distance_m": 1314.0,
   "start_elevation_m": 260.4343971233216,
   "end_elevation_m": 259.0054849239892,
   "start_xy": [
    267175.1120329171,
    256099.3427068224
   ],
   "end_xy": [
    267190.5318021635,
    256112.07510162267
   ]
  },
  "min_25m": {
   "gradient_pct": -6.6312108516269745,
   "start_distance_m": 1299.0,
   "end_distance_m": 1324.0,
   "midpoint_distance_m": 1311.5,
   "start_elevation_m": 260.6632876368959,
   "end_elevation_m": 259.0054849239892,
   "start_xy": [
    267171.2770642439,
    256096.1344343942
   ],
   "end_xy": [
    267190.5318021635,
    256112.07510162267
   ]
  },
  "min_50m": {
   "gradient_pct": -4.963585451507356,
   "start_distance_m": 1281.0,
   "end_distance_m": 1331.0,
   "midpoint_distance_m": 1306.0,
   "start_elevation_m": 261.31605928326366,
   "end_elevation_m": 258.83426655751,
   "start_xy": [
    267157.4716503179,
    256084.58408846645
   ],
   "end_xy": [
    267196.13479993964,
    256116.27109995476
   ]
  },
  "min_100m": {
   "gradient_pct": -1.8173770503965443,
   "start_distance_m": 1242.0,
   "end_distance_m": 1342.0,
   "midpoint_distance_m": 1292.0,
   "start_elevation_m": 260.60898596748257,
   "end_elevation_m": 258.791608917086,
   "start_xy": [
    267127.4141292631,
    256059.73383425592
   ],
   "end_xy": [
    267204.9393670794,
    256122.86500234777
   ]
  }
 },
 "diagnostic_window_maxima": {
  "max_2m": {
   "gradient_pct": 30.73923079307548,
   "start_distance_m": 181.0,
   "end_distance_m": 183.0,
   "midpoint_distance_m": 182.0,
   "start_elevation_m": 171.57157751295867,
   "end_elevation_m": 172.18636212882018,
   "start_xy": [
    266203.6372417596,
    255736.18605092913
   ],
   "end_xy": [
    266205.62836180517,
    255736.3743076019
   ]
  },
  "max_3m": {
   "gradient_pct": 27.944578947951488,
   "start_distance_m": 180.0,
   "end_distance_m": 183.0,
   "midpoint_distance_m": 181.5,
   "start_elevation_m": 171.34802476038163,
   "end_elevation_m": 172.18636212882018,
   "start_xy": [
    266202.6416724544,
    255736.09202031227
   ],
   "end_xy": [
    266205.62836180517,
    255736.3743076019
   ]
  }
 },
 "diagnostic_note": "Windows <=3 m are at raster-noise scale (1-sigma raster noise alone is roughly +/-7 pp at 2 m and +/-5 pp at 3 m on a 1 m DTM). Diagnostic use only: never a headline or ranking value.",
 "quality_summary": {
  "structure_suppression": {
   "masked_fraction": 0.004,
   "windows_resited": [
    10.0,
    20.0,
    25.0,
    50.0,
    100.0
   ],
   "windows_unresolved": [],
   "minima_resited": [],
   "minima_unresolved": []
  },
  "texture_suppression": {
   "masked_fraction": 0.058,
   "windows_resited": [
    2.0,
    5.0,
    10.0
   ],
   "windows_unresolved": [],
   "minima_resited": [],
   "minima_unresolved": []
  },
  "texture_windows": {
   "rounds": 3,
   "windows_masked": [
    {
     "window_m": 25.0,
     "start_m": 619.0,
     "end_m": 644.0,
     "raw_pct": 22.5,
     "reason": "mask-edge"
    },
    {
     "window_m": 20.0,
     "start_m": 620.0,
     "end_m": 640.0,
     "raw_pct": 22.48,
     "reason": "mask-edge"
    },
    {
     "window_m": 5.0,
     "start_m": 710.0,
     "end_m": 715.0,
     "raw_pct": 37.09,
     "reason": "short-step"
    },
    {
     "window_m": 25.0,
     "start_m": 587.0,
     "end_m": 612.0,
     "raw_pct": 20.11,
     "reason": "mask-edge"
    },
    {
     "window_m": 20.0,
     "start_m": 592.0,
     "end_m": 612.0,
     "raw_pct": 20.69,
     "reason": "mask-edge"
    },
    {
     "window_m": 10.0,
     "start_m": 602.0,
     "end_m": 612.0,
     "raw_pct": 21.75,
     "reason": "mask-edge"
    },
    {
     "window_m": 10.0,
     "start_m": 649.0,
     "end_m": 659.0,
     "raw_pct": 18.8,
     "reason": "mask-edge"
    }
   ],
   "advisory": [],
   "unresolved": [],
   "unstable": [
    {
     "window_m": 5.0,
     "start_m": 607.0,
     "end_m": 612.0,
     "raw_pct": 25.1,
     "reason": "mask-edge",
     "perturbations": [
      "phase+0.000/mask+0",
      "phase+0.333/mask+1",
      "phase+0.667/mask-1"
     ],
     "perturbation_reasons": [
      "",
      "",
      "mask-edge"
     ]
    }
   ]
  },
  "overhead_obstruction": {
   "obstruction_threshold_m": 2.0,
   "obstructed_fraction": 0.217,
   "obstruction_max_height_m": 23.01,
   "flagged_windows_m": [
    2,
    3,
    5
   ]
  },
  "excluded_ranges_m": [
   [
    585.0,
    661.0
   ],
   [
    708.0,
    717.0
   ]
  ],
  "review": [
   "short_window_divergence"
  ],
  "extent": [
   "may_continue_beyond_end"
  ]
 },
 "provenance": {
  "analysis_version": "0.1.0",
  "run_manifest": {
   "manifest_version": "1",
   "code_git_sha": "cd1381c557ec0196a6c481fc125290b249b285c2",
   "code_git_dirty": "true",
   "analysis_version": "0.1.0",
   "analysis_config_digest": "sha256:faa4beed0662d2f6",
   "python": "3.14.4",
   "numpy": "2.5.3",
   "rasterio": "1.5.1",
   "pyproj": "3.8.0",
   "laspy": "2.7.0",
   "shapely": "2.1.2",
   "pyosmium": "4.3.1",
   "libosmium": "2.23.1",
   "gdal": "3.12.4",
   "proj": "9.8.1",
   "run_id": "remeasure-260920-uk",
   "road_pbf": "batch-wales-chunk023.pbf",
   "region_key": "wales",
   "crs": "EPSG:27700",
   "elevation_provider_key": "wales",
   "authority": "os-open-roads",
   "registry_pbf": "wales-2026-08-11.osm.pbf"
  },
  "sample_interval_m": 1.0,
  "interpolation": "bilinear",
  "smoothing": "none",
  "gradient_windows_m": [
   5.0,
   10.0,
   20.0,
   25.0,
   50.0,
   100.0
  ],
  "diagnostic_windows_m": [
   2.0,
   3.0
  ],
  "elevation_crs": "EPSG:27700",
  "elevation_resolution_m": 1.0,
  "elevation_tiles": [
   "data/cache/wales/dtm_1m/wg_del_22_266255_20220114dtm.tif",
   "data/cache/wales/dtm_1m/wg_del_22_266256_20220114dtm.tif",
   "data/cache/wales/dtm_1m/wg_del_22_267255_20220114dtm.tif",
   "data/cache/wales/dtm_1m/wg_del_22_267256_20220114dtm.tif"
  ],
  "calculated_at": "2026-09-21T02:18:13+00:00",
  "road_source": "OpenStreetMap (local PBF extract)",
  "road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
  "osm_pbf_path": "output/remeasure-260920/uk/batch-wales-chunk023.pbf",
  "osm_snapshot": "",
  "run_id": "remeasure-260920-uk",
  "elevation_provider": "Welsh Government",
  "elevation_dataset": "Welsh Government LiDAR 1m DTM (2020-2023)",
  "elevation_licence": "Open Government Licence v3 \u2014 \u00a9 Crown copyright Welsh Government",
  "elevation_catalogue_layer": "geonode:welsh_government_lidar_tile_catalogue_2020_2023",
  "elevation_tile_ids": [
   "wg_del_22_266255_20220114dtm.tif",
   "wg_del_22_266256_20220114dtm.tif",
   "wg_del_22_267255_20220114dtm.tif",
   "wg_del_22_267256_20220114dtm.tif"
  ],
  "elevation_capture_dates": [
   "14-01-2022"
  ],
  "climb_origin": "discovered",
  "structure_own_ways": "none \u2014 the route carried no way list; own decks unmasked",
  "suppression_unstable": [
   5.0
  ],
  "carriageway": {
   "stations": 65,
   "stations_resolved": 65,
   "width_median_m": 3.5,
   "width_p10_m": 2.1,
   "width_min_m": 0.5,
   "width_max_m": 11.0,
   "bounded_share": 0.292,
   "unbounded_share": 0.708,
   "confidence_median": 0.0,
   "width_median_bounded_m": 2.75,
   "window_m": [
    410.0,
    435.0
   ],
   "width_at_max25_m": 2.75,
   "window_stations": 6,
   "single_track": false,
   "single_track_rule": "PROVISIONAL (2026-09-15): width_p10_m <= 3.0 m with bounded_share >= 0.6; recorded, not a rule",
   "status": "ok",
   "source": "dtm",
   "station_m": 25.0,
   "window_station_m": 5.0,
   "halfwidth_m": 6.0,
   "step_m": 0.25,
   "level_tol_m": 0.12,
   "break_min_m": 0.3,
   "stations_failed": 0,
   "hedge_to_hedge": {
    "stations": 65,
    "stations_resolved": 65,
    "width_median_m": 4.5,
    "width_p10_m": 1.0,
    "width_min_m": 0.5,
    "width_max_m": 12.0,
    "bounded_share": 0.877,
    "unbounded_share": 0.123,
    "confidence_median": 1.0,
    "width_median_bounded_m": 4.25,
    "window_m": [
     410.0,
     435.0
    ],
    "width_at_max25_m": 6.0,
    "window_stations": 6,
    "status": "ok",
    "source": "dsm",
    "station_m": 25.0,
    "window_station_m": 5.0,
    "halfwidth_m": 6.0,
    "step_m": 0.25,
    "level_tol_m": 0.5,
    "break_min_m": 0.3,
    "stations_failed": 0
   }
  },
  "remeasured": {
   "on": "2026-09-21",
   "why": "corpus re-measure 2026-09-21: a mask that exists today reaching a page published before it did; fallers only (Peter: fold the fallers)",
   "published_max25_pct": 25.39,
   "max25_pct": 16.95
  },
  "license": "ODbL-1.0",
  "license_url": "https://howsteep.org/licensing"
 },
 "area": {
  "place": "Llanddewi Brefi",
  "county": "Sir Ceredigion - Ceredigion"
 }
}