{
 "ocl_version": "0.1.0",
 "name": "Sanctuary Lane",
 "slug": "sanctuary-lane",
 "confidence": "A",
 "reported_claims": [],
 "ladder": [
  {
   "window_m": 2.0,
   "max_gradient_pct": 27.02766760247073,
   "diagnostic": true,
   "flags": [],
   "start_distance_m": 765.0,
   "end_distance_m": 767.0,
   "start_elevation_m": 270.62167539224845,
   "end_elevation_m": 271.16222874429786,
   "min_gradient_pct": -12.376979509892294
  },
  {
   "window_m": 3.0,
   "max_gradient_pct": 25.79745296268925,
   "diagnostic": true,
   "flags": [],
   "start_distance_m": 747.0,
   "end_distance_m": 750.0,
   "start_elevation_m": 267.10422478480695,
   "end_elevation_m": 267.8781483736876,
   "min_gradient_pct": -11.494858343983575
  },
  {
   "window_m": 5.0,
   "max_gradient_pct": 25.121103481750424,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 765.0,
   "end_distance_m": 770.0,
   "start_elevation_m": 270.62167539224845,
   "end_elevation_m": 271.87773056633597,
   "min_gradient_pct": -11.004998189412731
  },
  {
   "window_m": 10.0,
   "max_gradient_pct": 23.512269364267127,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 765.0,
   "end_distance_m": 775.0,
   "start_elevation_m": 270.62167539224845,
   "end_elevation_m": 272.97290232867516,
   "min_gradient_pct": -9.72231173087863
  },
  {
   "window_m": 20.0,
   "max_gradient_pct": 22.446732985745257,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 765.0,
   "end_distance_m": 785.0,
   "start_elevation_m": 270.62167539224845,
   "end_elevation_m": 275.1110219893975,
   "min_gradient_pct": -8.505448398954627
  },
  {
   "window_m": 25.0,
   "max_gradient_pct": 22.262488265046613,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 763.0,
   "end_distance_m": 788.0,
   "start_elevation_m": 270.21668330550983,
   "end_elevation_m": 275.7823053717715,
   "min_gradient_pct": -8.213168996785612
  },
  {
   "window_m": 50.0,
   "max_gradient_pct": 20.767856533527947,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 741.0,
   "end_distance_m": 791.0,
   "start_elevation_m": 266.0413778541408,
   "end_elevation_m": 276.4253061209048,
   "min_gradient_pct": -6.494916773346517
  },
  {
   "window_m": 100.0,
   "max_gradient_pct": 20.43265760243196,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 696.0,
   "end_distance_m": 796.0,
   "start_elevation_m": 256.8747174158177,
   "end_elevation_m": 277.3073750182497,
   "min_gradient_pct": -2.0832208960433434
  }
 ],
 "shape": {
  "ascent_concentration": 0.431,
  "concentration_window_frac": 0.25,
  "longest_pitch_10pct_m": 320.0,
  "shape_class": "sustained"
 },
 "length_m": 1126.3641398666343,
 "start_elevation_m": 212.85774481811524,
 "end_elevation_m": 321.5187530517578,
 "endpoint_gain_m": 108.66100823364258,
 "overall_gradient_pct": 9.647058565492722,
 "accumulated_ascent_m": 112.45247913866282,
 "window_maxima": {
  "max_5m": {
   "gradient_pct": 25.121103481750424,
   "start_distance_m": 765.0,
   "end_distance_m": 770.0,
   "midpoint_distance_m": 767.5,
   "start_elevation_m": 270.62167539224845,
   "end_elevation_m": 271.87773056633597,
   "start_xy": [
    295032.73897122487,
    131603.7362712146
   ],
   "end_xy": [
    295028.8701079192,
    131606.9035881742
   ]
  },
  "max_10m": {
   "gradient_pct": 23.512269364267127,
   "start_distance_m": 765.0,
   "end_distance_m": 775.0,
   "midpoint_distance_m": 770.0,
   "start_elevation_m": 270.62167539224845,
   "end_elevation_m": 272.97290232867516,
   "start_xy": [
    295032.73897122487,
    131603.7362712146
   ],
   "end_xy": [
    295025.0012446136,
    131610.07090513376
   ]
  },
  "max_20m": {
   "gradient_pct": 22.446732985745257,
   "start_distance_m": 765.0,
   "end_distance_m": 785.0,
   "midpoint_distance_m": 775.0,
   "start_elevation_m": 270.62167539224845,
   "end_elevation_m": 275.1110219893975,
   "start_xy": [
    295032.73897122487,
    131603.7362712146
   ],
   "end_xy": [
    295017.2635180024,
    131616.40553905294
   ]
  },
  "max_25m": {
   "gradient_pct": 22.262488265046613,
   "start_distance_m": 763.0,
   "end_distance_m": 788.0,
   "midpoint_distance_m": 775.5,
   "start_elevation_m": 270.21668330550983,
   "end_elevation_m": 275.7823053717715,
   "start_xy": [
    295034.2865165471,
    131602.46934443078
   ],
   "end_xy": [
    295014.942200019,
    131618.3059292287
   ]
  },
  "max_50m": {
   "gradient_pct": 20.767856533527947,
   "start_distance_m": 741.0,
   "end_distance_m": 791.0,
   "midpoint_distance_m": 766.0,
   "start_elevation_m": 266.0413778541408,
   "end_elevation_m": 276.4253061209048,
   "start_xy": [
    295051.3095150918,
    131588.53314980862
   ],
   "end_xy": [
    295012.62088203564,
    131620.20631940445
   ]
  },
  "max_100m": {
   "gradient_pct": 20.43265760243196,
   "start_distance_m": 696.0,
   "end_distance_m": 796.0,
   "midpoint_distance_m": 746.0,
   "start_elevation_m": 256.8747174158177,
   "end_elevation_m": 277.3073750182497,
   "start_xy": [
    295089.55327227677,
    131565.70442249914
   ],
   "end_xy": [
    295008.75201873004,
    131623.373636364
   ]
  }
 },
 "window_minima": {
  "min_5m": {
   "gradient_pct": -11.004998189412731,
   "start_distance_m": 156.0,
   "end_distance_m": 161.0,
   "midpoint_distance_m": 158.5,
   "start_elevation_m": 220.16237746686582,
   "end_elevation_m": 219.61212755739518,
   "start_xy": [
    295489.49079332367,
    131244.15488891915
   ],
   "end_xy": [
    295488.9962335065,
    131249.13036985946
   ]
  },
  "min_10m": {
   "gradient_pct": -9.72231173087863,
   "start_distance_m": 155.0,
   "end_distance_m": 165.0,
   "midpoint_distance_m": 160.0,
   "start_elevation_m": 220.21551968326796,
   "end_elevation_m": 219.2432885101801,
   "start_xy": [
    295489.58970528713,
    131243.1597927311
   ],
   "end_xy": [
    295488.60043485527,
    131253.11073961208
   ]
  },
  "min_20m": {
   "gradient_pct": -8.505448398954627,
   "start_distance_m": 155.0,
   "end_distance_m": 175.0,
   "midpoint_distance_m": 165.0,
   "start_elevation_m": 220.21551968326796,
   "end_elevation_m": 218.51443000347703,
   "start_xy": [
    295489.58970528713,
    131243.1597927311
   ],
   "end_xy": [
    295487.60995199264,
    131263.06156589428
   ]
  },
  "min_25m": {
   "gradient_pct": -8.213168996785612,
   "start_distance_m": 149.0,
   "end_distance_m": 174.0,
   "midpoint_distance_m": 161.5,
   "start_elevation_m": 220.63407157765178,
   "end_elevation_m": 218.58077932845538,
   "start_xy": [
    295490.1831770677,
    131237.18921560273
   ],
   "end_xy": [
    295487.7090002789,
    131262.06648326607
   ]
  },
  "min_50m": {
   "gradient_pct": -6.494916773346517,
   "start_distance_m": 140.0,
   "end_distance_m": 190.0,
   "midpoint_distance_m": 165.0,
   "start_elevation_m": 221.02264856868305,
   "end_elevation_m": 217.7751901820098,
   "start_xy": [
    295491.0733847387,
    131228.2333499102
   ],
   "end_xy": [
    295486.1242276987,
    131277.98780531762
   ]
  },
  "min_100m": {
   "gradient_pct": -2.0832208960433434,
   "start_distance_m": 121.0,
   "end_distance_m": 221.0,
   "midpoint_distance_m": 171.0,
   "start_elevation_m": 220.16846137337876,
   "end_elevation_m": 218.08524047733542,
   "start_xy": [
    295494.70832920657,
    131209.67161016088
   ],
   "end_xy": [
    295467.7523098973,
    131301.36486001132
   ]
  }
 },
 "diagnostic_window_maxima": {
  "max_2m": {
   "gradient_pct": 27.02766760247073,
   "start_distance_m": 765.0,
   "end_distance_m": 767.0,
   "midpoint_distance_m": 766.0,
   "start_elevation_m": 270.62167539224845,
   "end_elevation_m": 271.16222874429786,
   "start_xy": [
    295032.73897122487,
    131603.7362712146
   ],
   "end_xy": [
    295031.1914259026,
    131605.00319799845
   ]
  },
  "max_3m": {
   "gradient_pct": 25.79745296268925,
   "start_distance_m": 747.0,
   "end_distance_m": 750.0,
   "midpoint_distance_m": 748.5,
   "start_elevation_m": 267.10422478480695,
   "end_elevation_m": 267.8781483736876,
   "start_xy": [
    295046.66687912506,
    131592.33393016012
   ],
   "end_xy": [
    295044.3455611417,
    131594.23432033588
   ]
  }
 },
 "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": 0.042,
   "obstruction_max_height_m": 12.09,
   "flagged_windows_m": []
  },
  "review": [],
  "extent": [
   "may_continue_beyond_end"
  ]
 },
 "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/SS9030.tif",
   "data/cache/england/bulk_dtm_1m/SS9530.tif"
  ],
  "calculated_at": "2026-08-20T19:18:57+00:00",
  "road_source": "OpenStreetMap (local PBF extract)",
  "road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
  "osm_pbf_path": "data/cache/pbf/england-2026-08-12.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": [
   "SS9030.tif",
   "SS9530.tif"
  ],
  "climb_origin": "discovered",
  "notes": "Coarse pass: max 12.4% over 200 m (Terrain 50), gain 45.5 m over 502 m way. EXTENDED by graph walk: +1 segment(s) at base, +1 at top (stop: base=no_descending_continuation, top=no_ascending_continuation; min_avg=2.0%). Review before adopting. DEDUPE: absorbed 1 overlapping proposal(s): sanctuary-lane-2 ADOPTED (England launch slice 2026-08-16): clean-steep.",
  "license": "ODbL-1.0",
  "license_url": "https://howsteep.org/licensing.html"
 },
 "area": {
  "place": "Brompton Regis",
  "county": "Somerset"
 }
}