{
 "ocl_version": "0.1.0",
 "name": "Strait Lane",
 "slug": "strait-lane",
 "confidence": "A",
 "reported_claims": [],
 "ladder": [
  {
   "window_m": 2.0,
   "max_gradient_pct": 31.347748765698213,
   "diagnostic": true,
   "flags": [],
   "start_distance_m": 238.0,
   "end_distance_m": 240.0,
   "start_elevation_m": 138.48868335417635,
   "end_elevation_m": 139.1156383294903,
   "min_gradient_pct": -2.795865215910709
  },
  {
   "window_m": 3.0,
   "max_gradient_pct": 30.31460287252609,
   "diagnostic": true,
   "flags": [],
   "start_distance_m": 237.0,
   "end_distance_m": 240.0,
   "start_elevation_m": 138.20620024331453,
   "end_elevation_m": 139.1156383294903,
   "min_gradient_pct": -2.166370558516917
  },
  {
   "window_m": 5.0,
   "max_gradient_pct": 29.57677941028919,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 235.0,
   "end_distance_m": 240.0,
   "start_elevation_m": 137.63679935897585,
   "end_elevation_m": 139.1156383294903,
   "min_gradient_pct": -2.130763481326312
  },
  {
   "window_m": 10.0,
   "max_gradient_pct": 28.665663024023047,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 230.0,
   "end_distance_m": 240.0,
   "start_elevation_m": 136.249072027088,
   "end_elevation_m": 139.1156383294903,
   "min_gradient_pct": -1.6172852542041483
  },
  {
   "window_m": 20.0,
   "max_gradient_pct": 26.58869352636401,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 224.0,
   "end_distance_m": 244.0,
   "start_elevation_m": 134.7580210286344,
   "end_elevation_m": 140.0757597339072,
   "min_gradient_pct": -0.4081207239754292
  },
  {
   "window_m": 25.0,
   "max_gradient_pct": 25.845405970875504,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 223.0,
   "end_distance_m": 248.0,
   "start_elevation_m": 134.53873673950352,
   "end_elevation_m": 141.0000882322224,
   "min_gradient_pct": 0.0007084117846147819
  },
  {
   "window_m": 50.0,
   "max_gradient_pct": 20.17361726744747,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 201.0,
   "end_distance_m": 251.0,
   "start_elevation_m": 131.41679757292994,
   "end_elevation_m": 141.50360620665367,
   "min_gradient_pct": 1.032271409908617
  },
  {
   "window_m": 100.0,
   "max_gradient_pct": 17.90530032431022,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 156.0,
   "end_distance_m": 256.0,
   "start_elevation_m": 124.30186605349309,
   "end_elevation_m": 142.2071663778033,
   "min_gradient_pct": 4.4041988345095575
  }
 ],
 "shape": {
  "ascent_concentration": 0.459,
  "concentration_window_frac": 0.25,
  "longest_pitch_10pct_m": 183.0,
  "shape_class": "stepped"
 },
 "length_m": 381.4673210558838,
 "start_elevation_m": 112.11051939630164,
 "end_elevation_m": 149.71900460484133,
 "endpoint_gain_m": 37.60848520853969,
 "overall_gradient_pct": 9.858900915664584,
 "accumulated_ascent_m": 37.800649672223415,
 "window_maxima": {
  "max_5m": {
   "gradient_pct": 29.57677941028919,
   "start_distance_m": 235.0,
   "end_distance_m": 240.0,
   "midpoint_distance_m": 237.5,
   "start_elevation_m": 137.63679935897585,
   "end_elevation_m": 139.1156383294903,
   "start_xy": [
    356528.25355283305,
    454535.2063242261
   ],
   "end_xy": [
    356532.32102354657,
    454538.1141897655
   ]
  },
  "max_10m": {
   "gradient_pct": 28.665663024023047,
   "start_distance_m": 230.0,
   "end_distance_m": 240.0,
   "midpoint_distance_m": 235.0,
   "start_elevation_m": 136.249072027088,
   "end_elevation_m": 139.1156383294903,
   "start_xy": [
    356524.1860821196,
    454532.2984586868
   ],
   "end_xy": [
    356532.32102354657,
    454538.1141897655
   ]
  },
  "max_20m": {
   "gradient_pct": 26.58869352636401,
   "start_distance_m": 224.0,
   "end_distance_m": 244.0,
   "midpoint_distance_m": 234.0,
   "start_elevation_m": 134.7580210286344,
   "end_elevation_m": 140.0757597339072,
   "start_xy": [
    356519.3051172634,
    454528.80902003957
   ],
   "end_xy": [
    356535.57500011736,
    454540.4404821969
   ]
  },
  "max_25m": {
   "gradient_pct": 25.845405970875504,
   "start_distance_m": 223.0,
   "end_distance_m": 248.0,
   "midpoint_distance_m": 235.5,
   "start_elevation_m": 134.53873673950352,
   "end_elevation_m": 141.0000882322224,
   "start_xy": [
    356518.4916231207,
    454528.2274469317
   ],
   "end_xy": [
    356538.82897668815,
    454542.7667746284
   ]
  },
  "max_50m": {
   "gradient_pct": 20.17361726744747,
   "start_distance_m": 201.0,
   "end_distance_m": 251.0,
   "midpoint_distance_m": 226.0,
   "start_elevation_m": 131.41679757292994,
   "end_elevation_m": 141.50360620665367,
   "start_xy": [
    356500.5947519814,
    454515.43283855857
   ],
   "end_xy": [
    356541.2694591162,
    454544.511493952
   ]
  },
  "max_100m": {
   "gradient_pct": 17.90530032431022,
   "start_distance_m": 156.0,
   "end_distance_m": 256.0,
   "midpoint_distance_m": 206.0,
   "start_elevation_m": 124.30186605349309,
   "end_elevation_m": 142.2071663778033,
   "start_xy": [
    356463.98751555994,
    454489.26204870443
   ],
   "end_xy": [
    356545.33692982973,
    454547.4193594914
   ]
  }
 },
 "window_minima": {
  "min_5m": {
   "gradient_pct": -2.130763481326312,
   "start_distance_m": 0.0,
   "end_distance_m": 5.0,
   "midpoint_distance_m": 2.5,
   "start_elevation_m": 112.11051939630164,
   "end_elevation_m": 112.00398122223532,
   "start_xy": [
    356353.029,
    454381.636
   ],
   "end_xy": [
    356357.20624788763,
    454384.3838355273
   ]
  },
  "min_10m": {
   "gradient_pct": -1.6172852542041483,
   "start_distance_m": 0.0,
   "end_distance_m": 10.0,
   "midpoint_distance_m": 5.0,
   "start_elevation_m": 112.11051939630164,
   "end_elevation_m": 111.94879087088123,
   "start_xy": [
    356353.029,
    454381.636
   ],
   "end_xy": [
    356361.3834957753,
    454387.1316710546
   ]
  },
  "min_20m": {
   "gradient_pct": -0.4081207239754292,
   "start_distance_m": 0.0,
   "end_distance_m": 20.0,
   "midpoint_distance_m": 10.0,
   "start_elevation_m": 112.11051939630164,
   "end_elevation_m": 112.02889525150655,
   "start_xy": [
    356353.029,
    454381.636
   ],
   "end_xy": [
    356369.7379915506,
    454392.6273421092
   ]
  },
  "min_25m": {
   "gradient_pct": 0.0007084117846147819,
   "start_distance_m": 0.0,
   "end_distance_m": 25.0,
   "midpoint_distance_m": 12.5,
   "start_elevation_m": 112.11051939630164,
   "end_elevation_m": 112.1106964992478,
   "start_xy": [
    356353.029,
    454381.636
   ],
   "end_xy": [
    356373.9116434024,
    454395.3802437458
   ]
  },
  "min_50m": {
   "gradient_pct": 1.032271409908617,
   "start_distance_m": 0.0,
   "end_distance_m": 50.0,
   "midpoint_distance_m": 25.0,
   "start_elevation_m": 112.11051939630164,
   "end_elevation_m": 112.62665510125595,
   "start_xy": [
    356353.029,
    454381.636
   ],
   "end_xy": [
    356393.65330969077,
    454410.70961722435
   ]
  },
  "min_100m": {
   "gradient_pct": 4.4041988345095575,
   "start_distance_m": 0.0,
   "end_distance_m": 100.0,
   "midpoint_distance_m": 50.0,
   "start_elevation_m": 112.11051939630164,
   "end_elevation_m": 116.5147182308112,
   "start_xy": [
    356353.029,
    454381.636
   ],
   "end_xy": [
    356425.6743570678,
    454448.7042924156
   ]
  }
 },
 "diagnostic_window_maxima": {
  "max_2m": {
   "gradient_pct": 31.347748765698213,
   "start_distance_m": 238.0,
   "end_distance_m": 240.0,
   "midpoint_distance_m": 239.0,
   "start_elevation_m": 138.48868335417635,
   "end_elevation_m": 139.1156383294903,
   "start_xy": [
    356530.6940352612,
    454536.95104354975
   ],
   "end_xy": [
    356532.32102354657,
    454538.1141897655
   ]
  },
  "max_3m": {
   "gradient_pct": 30.31460287252609,
   "start_distance_m": 237.0,
   "end_distance_m": 240.0,
   "midpoint_distance_m": 238.5,
   "start_elevation_m": 138.20620024331453,
   "end_elevation_m": 139.1156383294903,
   "start_xy": [
    356529.88054111844,
    454536.36947044183
   ],
   "end_xy": [
    356532.32102354657,
    454538.1141897655
   ]
  }
 },
 "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": {
  "overhead_obstruction": {
   "obstruction_threshold_m": 2.0,
   "obstructed_fraction": 0.078,
   "obstruction_max_height_m": 22.31,
   "flagged_windows_m": []
  },
  "review": [],
  "extent": []
 },
 "provenance": {
  "analysis_version": "0.1.0",
  "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/england/bulk_dtm_1m/SD5550.tif"
  ],
  "calculated_at": "2026-08-15T21:34:36+00:00",
  "road_source": "OpenStreetMap (local PBF extract)",
  "road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
  "osm_pbf_path": "data/cache/pbf/england-2026-08-12-roads.osm.pbf",
  "osm_snapshot": "2026-08-12T20:21:46Z",
  "elevation_provider": "Environment Agency",
  "elevation_dataset": "EA LIDAR Composite DTM 1m (2022)",
  "elevation_licence": "Open Government Licence v3 \u2014 \u00a9 Environment Agency",
  "elevation_coverage_id": "13787b9a-26a4-4775-8523-806d13af58fc__Lidar_Composite_Elevation_DTM_1m",
  "elevation_tile_ids": [
   "SD5550.tif"
  ],
  "climb_origin": "discovered",
  "notes": "Coarse pass: max 14.8% over 200 m (Terrain 50), gain 33.6 m over 233 m way. EXTENDED by graph walk: +1 segment(s) at base, +2 at top (stop: base=no_descending_continuation, top=no_ascending_continuation; min_avg=2.0%). Review before adopting."
 },
 "area": {
  "place": "Abbeystead",
  "county": "Lancashire"
 }
}