{
 "ocl_version": "0.1.0",
 "name": "Hollow Combe to Ember Combe",
 "slug": "discovered-lane-51-1734-3-6039",
 "confidence": "A",
 "reported_claims": [],
 "ladder": [
  {
   "window_m": 2.0,
   "max_gradient_pct": 41.83459250429564,
   "diagnostic": true,
   "flags": [],
   "start_distance_m": 472.0,
   "end_distance_m": 474.0,
   "start_elevation_m": 226.23613329599397,
   "end_elevation_m": 227.07282514607988,
   "min_gradient_pct": -27.25489637937102
  },
  {
   "window_m": 3.0,
   "max_gradient_pct": 36.41523410671823,
   "diagnostic": true,
   "flags": [],
   "start_distance_m": 143.0,
   "end_distance_m": 146.0,
   "start_elevation_m": 211.80152266650398,
   "end_elevation_m": 212.89397968970553,
   "min_gradient_pct": -21.817590874789516
  },
  {
   "window_m": 5.0,
   "max_gradient_pct": 29.06816673697449,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 142.0,
   "end_distance_m": 147.0,
   "start_elevation_m": 211.62222591325383,
   "end_elevation_m": 213.07563425010255,
   "min_gradient_pct": -17.589414314374494
  },
  {
   "window_m": 10.0,
   "max_gradient_pct": 21.2932003533939,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 986.0,
   "end_distance_m": 996.0,
   "start_elevation_m": 260.8076213144159,
   "end_elevation_m": 262.9369413497553,
   "min_gradient_pct": -10.45628226062945
  },
  {
   "window_m": 20.0,
   "max_gradient_pct": 18.792024243595904,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 976.0,
   "end_distance_m": 996.0,
   "start_elevation_m": 259.1785365010361,
   "end_elevation_m": 262.9369413497553,
   "min_gradient_pct": -7.8272090242828085
  },
  {
   "window_m": 25.0,
   "max_gradient_pct": 17.540188817235503,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 974.0,
   "end_distance_m": 999.0,
   "start_elevation_m": 258.8768115705153,
   "end_elevation_m": 263.2618587748242,
   "min_gradient_pct": -7.353377350210053
  },
  {
   "window_m": 50.0,
   "max_gradient_pct": 15.83465020603137,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 3308.0,
   "end_distance_m": 3358.0,
   "start_elevation_m": 414.9303387472477,
   "end_elevation_m": 422.84766385026336,
   "min_gradient_pct": -4.908687448952605
  },
  {
   "window_m": 100.0,
   "max_gradient_pct": 15.467089581919652,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 3305.0,
   "end_distance_m": 3405.0,
   "start_elevation_m": 414.471323780509,
   "end_elevation_m": 429.93841336242866,
   "min_gradient_pct": -4.830106643586589
  }
 ],
 "shape": {
  "ascent_concentration": 0.371,
  "concentration_window_frac": 0.25,
  "longest_pitch_10pct_m": 254.0,
  "shape_class": "sustained"
 },
 "length_m": 5091.1190154940905,
 "start_elevation_m": 201.62454269447784,
 "end_elevation_m": 452.5522997521974,
 "endpoint_gain_m": 250.9277570577196,
 "overall_gradient_pct": 4.928734847762485,
 "accumulated_ascent_m": 298.99235433245406,
 "window_maxima": {
  "max_5m": {
   "gradient_pct": 29.06816673697449,
   "start_distance_m": 142.0,
   "end_distance_m": 147.0,
   "midpoint_distance_m": 144.5,
   "start_elevation_m": 211.62222591325383,
   "end_elevation_m": 213.07563425010255,
   "start_xy": [
    289650.3389154353,
    143063.93291589073
   ],
   "end_xy": [
    289645.7016925236,
    143065.8027190001
   ]
  },
  "max_10m": {
   "gradient_pct": 21.2932003533939,
   "start_distance_m": 986.0,
   "end_distance_m": 996.0,
   "midpoint_distance_m": 991.0,
   "start_elevation_m": 260.8076213144159,
   "end_elevation_m": 262.9369413497553,
   "start_xy": [
    289282.24657259183,
    143092.74156691172
   ],
   "end_xy": [
    289288.67274583475,
    143100.35991394072
   ]
  },
  "max_20m": {
   "gradient_pct": 18.792024243595904,
   "start_distance_m": 976.0,
   "end_distance_m": 996.0,
   "midpoint_distance_m": 986.0,
   "start_elevation_m": 259.1785365010361,
   "end_elevation_m": 262.9369413497553,
   "start_xy": [
    289276.758249216,
    143084.38224238623
   ],
   "end_xy": [
    289288.67274583475,
    143100.35991394072
   ]
  },
  "max_25m": {
   "gradient_pct": 17.540188817235503,
   "start_distance_m": 974.0,
   "end_distance_m": 999.0,
   "midpoint_distance_m": 986.5,
   "start_elevation_m": 258.8768115705153,
   "end_elevation_m": 263.2618587748242,
   "start_xy": [
    289275.66058454086,
    143082.71037748113
   ],
   "end_xy": [
    289290.73158193997,
    143102.54192995623
   ]
  },
  "max_50m": {
   "gradient_pct": 15.83465020603137,
   "start_distance_m": 3308.0,
   "end_distance_m": 3358.0,
   "midpoint_distance_m": 3333.0,
   "start_elevation_m": 414.9303387472477,
   "end_elevation_m": 422.84766385026336,
   "start_xy": [
    287374.0832799373,
    142268.6172280346
   ],
   "end_xy": [
    287342.1830651994,
    142230.34773824844
   ]
  },
  "max_100m": {
   "gradient_pct": 15.467089581919652,
   "start_distance_m": 3305.0,
   "end_distance_m": 3405.0,
   "midpoint_distance_m": 3355.0,
   "start_elevation_m": 414.471323780509,
   "end_elevation_m": 429.93841336242866,
   "start_xy": [
    287376.30010489566,
    142270.63853629996
   ],
   "end_xy": [
    287307.63675973593,
    142198.47999940766
   ]
  }
 },
 "window_minima": {
  "min_5m": {
   "gradient_pct": -17.589414314374494,
   "start_distance_m": 459.0,
   "end_distance_m": 464.0,
   "midpoint_distance_m": 461.5,
   "start_elevation_m": 226.702512522154,
   "end_elevation_m": 225.82304180643527,
   "start_xy": [
    289347.3246617045,
    143038.74187585298
   ],
   "end_xy": [
    289342.7069633567,
    143036.8243615429
   ]
  },
  "min_10m": {
   "gradient_pct": -10.45628226062945,
   "start_distance_m": 458.0,
   "end_distance_m": 468.0,
   "midpoint_distance_m": 463.0,
   "start_elevation_m": 226.66572468675616,
   "end_elevation_m": 225.62009646069322,
   "start_xy": [
    289348.24785665923,
    143039.126207839
   ],
   "end_xy": [
    289339.0127472187,
    143035.29048829988
   ]
  },
  "min_20m": {
   "gradient_pct": -7.8272090242828085,
   "start_distance_m": 187.0,
   "end_distance_m": 207.0,
   "midpoint_distance_m": 197.0,
   "start_elevation_m": 213.6984672202922,
   "end_elevation_m": 212.13302541543564,
   "start_xy": [
    289606.8599884877,
    143072.0084494249
   ],
   "end_xy": [
    289587.59989733266,
    143066.69108383782
   ]
  },
  "min_25m": {
   "gradient_pct": -7.353377350210053,
   "start_distance_m": 176.0,
   "end_distance_m": 201.0,
   "midpoint_distance_m": 188.5,
   "start_elevation_m": 214.44841079863758,
   "end_elevation_m": 212.61006646108507,
   "start_xy": [
    289617.7825717434,
    143072.42923339803
   ],
   "end_xy": [
    289593.26666249556,
    143068.65860040282
   ]
  },
  "min_50m": {
   "gradient_pct": -4.908687448952605,
   "start_distance_m": 4630.0,
   "end_distance_m": 4680.0,
   "midpoint_distance_m": 4655.0,
   "start_elevation_m": 466.50331598976186,
   "end_elevation_m": 464.04897226528556,
   "start_xy": [
    286440.5671871734,
    141392.80721704834
   ],
   "end_xy": [
    286397.21108572657,
    141368.0646735871
   ]
  },
  "min_100m": {
   "gradient_pct": -4.830106643586589,
   "start_distance_m": 4579.0,
   "end_distance_m": 4679.0,
   "midpoint_distance_m": 4629.0,
   "start_elevation_m": 468.91880547595866,
   "end_elevation_m": 464.0886988323721,
   "start_xy": [
    286482.61202719895,
    141421.5309820633
   ],
   "end_xy": [
    286398.00186428527,
    141368.67677592425
   ]
  }
 },
 "diagnostic_window_maxima": {
  "max_2m": {
   "gradient_pct": 41.83459250429564,
   "start_distance_m": 472.0,
   "end_distance_m": 474.0,
   "midpoint_distance_m": 473.0,
   "start_elevation_m": 226.23613329599397,
   "end_elevation_m": 227.07282514607988,
   "start_xy": [
    289335.3185310807,
    143033.7566150569
   ],
   "end_xy": [
    289333.4714230117,
    143032.98967843538
   ]
  },
  "max_3m": {
   "gradient_pct": 36.41523410671823,
   "start_distance_m": 143.0,
   "end_distance_m": 146.0,
   "midpoint_distance_m": 144.5,
   "start_elevation_m": 211.80152266650398,
   "end_elevation_m": 212.89397968970553,
   "start_xy": [
    289649.41147085297,
    143064.3068765126
   ],
   "end_xy": [
    289646.62913710595,
    143065.4287583782
   ]
  }
 },
 "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": 0.038,
   "obstruction_max_height_m": 27.51,
   "flagged_windows_m": []
  },
  "review": [],
  "extent": [],
  "suggested_summit_cut_m": 4133.0,
  "trailing_descent_m": 28.0
 },
 "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/SS8540.tif"
  ],
  "calculated_at": "2026-08-15T05:15:47+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": [
   "SS8540.tif"
  ],
  "climb_origin": "discovered",
  "notes": "Coarse pass: max 14.6% over 200 m (Terrain 50), gain 225.3 m over 4610 m way. EXTENDED by graph walk: +4 segment(s) at base, +0 at top (stop: base=no_descending_continuation, top=no_ascending_continuation; min_avg=2.0%). Review before adopting. DEDUPE: absorbed 1 overlapping proposal(s): discovered-lane-51-1796-3-6064",
  "naming_note": "auto-named from gazetteer (hypothesis, unreviewed); discovered as 'Discovered lane (51.1734, -3.6039)'"
 },
 "area": {
  "place": "Sweetworthy Combe",
  "county": "Somerset"
 }
}