{
 "ocl_version": "0.1.0",
 "name": "Porthallow to Talland",
 "slug": "discovered-lane-50-3392-4-4859",
 "confidence": "B",
 "reported_claims": [],
 "ladder": [
  {
   "window_m": 2.0,
   "max_gradient_pct": 46.632644913069754,
   "diagnostic": true,
   "flags": [
    "structure_excluded",
    "placement_excluded"
   ],
   "start_distance_m": 491.0,
   "end_distance_m": 493.0,
   "start_elevation_m": 76.10986463790137,
   "end_elevation_m": 77.04251753616276,
   "min_gradient_pct": -17.789981605473315,
   "suppressed_max_gradient_pct": 59.607269150486,
   "suppressed_location_m": [
    63.0,
    65.0
   ]
  },
  {
   "window_m": 3.0,
   "max_gradient_pct": 38.471471003701296,
   "diagnostic": true,
   "flags": [
    "placement_excluded"
   ],
   "start_distance_m": 125.0,
   "end_distance_m": 128.0,
   "start_elevation_m": 29.841662750005877,
   "end_elevation_m": 30.995806880116916,
   "min_gradient_pct": -8.413055208748096,
   "suppressed_max_gradient_pct": 46.83598607662477,
   "suppressed_location_m": [
    69.0,
    72.0
   ]
  },
  {
   "window_m": 5.0,
   "max_gradient_pct": 31.53298623913429,
   "diagnostic": false,
   "flags": [
    "placement_excluded"
   ],
   "start_distance_m": 124.0,
   "end_distance_m": 129.0,
   "start_elevation_m": 29.689412753628183,
   "end_elevation_m": 31.266062065584897,
   "min_gradient_pct": -4.586095534753696,
   "suppressed_max_gradient_pct": 35.24147159552925,
   "suppressed_location_m": [
    68.0,
    73.0
   ]
  },
  {
   "window_m": 10.0,
   "max_gradient_pct": 27.637467818199895,
   "diagnostic": false,
   "flags": [
    "structure_excluded",
    "placement_excluded",
    "canopy_or_structure"
   ],
   "start_distance_m": 103.0,
   "end_distance_m": 113.0,
   "start_elevation_m": 25.243939789692263,
   "end_elevation_m": 28.007686571512252,
   "min_gradient_pct": 1.2251095417667557,
   "suppressed_max_gradient_pct": 30.820511373777997,
   "suppressed_location_m": [
    62.0,
    72.0
   ]
  },
  {
   "window_m": 20.0,
   "max_gradient_pct": 23.467263348433818,
   "diagnostic": false,
   "flags": [
    "placement_excluded",
    "canopy_or_structure"
   ],
   "start_distance_m": 100.0,
   "end_distance_m": 120.0,
   "start_elevation_m": 24.63929757936047,
   "end_elevation_m": 29.332750249047233,
   "min_gradient_pct": 1.5559084266359946,
   "suppressed_max_gradient_pct": 24.801044305117053,
   "suppressed_location_m": [
    35.0,
    55.0
   ]
  },
  {
   "window_m": 25.0,
   "max_gradient_pct": 23.2924888792858,
   "diagnostic": false,
   "flags": [
    "structure_excluded",
    "placement_excluded",
    "canopy_or_structure"
   ],
   "start_distance_m": 104.0,
   "end_distance_m": 129.0,
   "start_elevation_m": 25.442939845763448,
   "end_elevation_m": 31.266062065584897,
   "min_gradient_pct": 1.6605329535483406,
   "suppressed_max_gradient_pct": 24.102774429916096,
   "suppressed_location_m": [
    40.0,
    65.0
   ]
  },
  {
   "window_m": 50.0,
   "max_gradient_pct": 21.033753260638555,
   "diagnostic": false,
   "flags": [
    "structure_excluded"
   ],
   "start_distance_m": 125.0,
   "end_distance_m": 175.0,
   "start_elevation_m": 29.841662750005877,
   "end_elevation_m": 40.358539380325155,
   "min_gradient_pct": 3.371525787873992,
   "suppressed_max_gradient_pct": 21.490164302093874,
   "suppressed_location_m": [
    23.0,
    73.0
   ]
  },
  {
   "window_m": 100.0,
   "max_gradient_pct": 19.50653381384519,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 94.0,
   "end_distance_m": 194.0,
   "start_elevation_m": 23.758197621824554,
   "end_elevation_m": 43.264731435669745,
   "min_gradient_pct": 5.405765734549107
  }
 ],
 "shape": {
  "ascent_concentration": 0.338,
  "concentration_window_frac": 0.25,
  "longest_pitch_10pct_m": 232.0,
  "shape_class": "sustained"
 },
 "length_m": 948.9999999999986,
 "start_elevation_m": 9.300970749956972,
 "end_elevation_m": 129.03024127339444,
 "endpoint_gain_m": 119.72927052343746,
 "overall_gradient_pct": 12.616361488244218,
 "accumulated_ascent_m": 121.3397474462167,
 "window_maxima": {
  "max_5m": {
   "gradient_pct": 31.53298623913429,
   "start_distance_m": 124.0,
   "end_distance_m": 129.0,
   "midpoint_distance_m": 126.5,
   "start_elevation_m": 29.689412753628183,
   "end_elevation_m": 31.266062065584897,
   "start_xy": [
    222732.8475833686,
    51659.4273734105
   ],
   "end_xy": [
    222737.79643306506,
    51660.14073634878
   ]
  },
  "max_10m": {
   "gradient_pct": 27.637467818199895,
   "start_distance_m": 103.0,
   "end_distance_m": 113.0,
   "midpoint_distance_m": 108.0,
   "start_elevation_m": 25.243939789692263,
   "end_elevation_m": 28.007686571512252,
   "start_xy": [
    222712.0624146434,
    51656.431249069705
   ],
   "end_xy": [
    222721.96011403634,
    51657.85797494627
   ]
  },
  "max_20m": {
   "gradient_pct": 23.467263348433818,
   "start_distance_m": 100.0,
   "end_distance_m": 120.0,
   "midpoint_distance_m": 110.0,
   "start_elevation_m": 24.63929757936047,
   "end_elevation_m": 29.332750249047233,
   "start_xy": [
    222709.2144065137,
    51655.49029195774
   ],
   "end_xy": [
    222728.8885036114,
    51658.85668305987
   ]
  },
  "max_25m": {
   "gradient_pct": 23.2924888792858,
   "start_distance_m": 104.0,
   "end_distance_m": 129.0,
   "midpoint_distance_m": 116.5,
   "start_elevation_m": 25.442939845763448,
   "end_elevation_m": 31.266062065584897,
   "start_xy": [
    222713.0521845827,
    51656.57392165736
   ],
   "end_xy": [
    222737.79643306506,
    51660.14073634878
   ]
  },
  "max_50m": {
   "gradient_pct": 21.033753260638555,
   "start_distance_m": 125.0,
   "end_distance_m": 175.0,
   "midpoint_distance_m": 150.0,
   "start_elevation_m": 29.841662750005877,
   "end_elevation_m": 40.358539380325155,
   "start_xy": [
    222733.83735330787,
    51659.57004599815
   ],
   "end_xy": [
    222783.4185148301,
    51658.66017255845
   ]
  },
  "max_100m": {
   "gradient_pct": 19.50653381384519,
   "start_distance_m": 94.0,
   "end_distance_m": 194.0,
   "midpoint_distance_m": 144.0,
   "start_elevation_m": 23.758197621824554,
   "end_elevation_m": 43.264731435669745,
   "start_xy": [
    222703.5214024027,
    51653.595640487954
   ],
   "end_xy": [
    222802.28114337934,
    51656.37955143559
   ]
  }
 },
 "window_minima": {
  "min_5m": {
   "gradient_pct": -4.586095534753696,
   "start_distance_m": 75.0,
   "end_distance_m": 80.0,
   "midpoint_distance_m": 77.5,
   "start_elevation_m": 22.597494666756862,
   "end_elevation_m": 22.368189890019178,
   "start_xy": [
    222685.49355605114,
    51647.59591083362
   ],
   "end_xy": [
    222690.23772614365,
    51649.17478705844
   ]
  },
  "min_10m": {
   "gradient_pct": 1.2251095417667557,
   "start_distance_m": 939.0,
   "end_distance_m": 949.0,
   "midpoint_distance_m": 944.0,
   "start_elevation_m": 128.90773031921776,
   "end_elevation_m": 129.03024127339444,
   "start_xy": [
    223480.16420923124,
    51892.54924513347
   ],
   "end_xy": [
    223486.9997645218,
    51899.84823025946
   ]
  },
  "min_20m": {
   "gradient_pct": 1.5559084266359946,
   "start_distance_m": 929.0,
   "end_distance_m": 949.0,
   "midpoint_distance_m": 939.0,
   "start_elevation_m": 128.71905958806724,
   "end_elevation_m": 129.03024127339444,
   "start_xy": [
    223473.32865394064,
    51885.25026000749
   ],
   "end_xy": [
    223486.9997645218,
    51899.84823025946
   ]
  },
  "min_25m": {
   "gradient_pct": 1.6605329535483406,
   "start_distance_m": 924.0,
   "end_distance_m": 949.0,
   "midpoint_distance_m": 936.5,
   "start_elevation_m": 128.61510803500735,
   "end_elevation_m": 129.03024127339444,
   "start_xy": [
    223469.91087629535,
    51881.6007674445
   ],
   "end_xy": [
    223486.9997645218,
    51899.84823025946
   ]
  },
  "min_50m": {
   "gradient_pct": 3.371525787873992,
   "start_distance_m": 899.0,
   "end_distance_m": 949.0,
   "midpoint_distance_m": 924.0,
   "start_elevation_m": 127.34447837945744,
   "end_elevation_m": 129.03024127339444,
   "start_xy": [
    223449.2250583573,
    51867.87934599231
   ],
   "end_xy": [
    223486.9997645218,
    51899.84823025946
   ]
  },
  "min_100m": {
   "gradient_pct": 5.405765734549107,
   "start_distance_m": 849.0,
   "end_distance_m": 949.0,
   "midpoint_distance_m": 899.0,
   "start_elevation_m": 123.62447553884533,
   "end_elevation_m": 129.03024127339444,
   "start_xy": [
    223405.95513257215,
    51842.825134319435
   ],
   "end_xy": [
    223486.9997645218,
    51899.84823025946
   ]
  }
 },
 "diagnostic_window_maxima": {
  "max_2m": {
   "gradient_pct": 46.632644913069754,
   "start_distance_m": 491.0,
   "end_distance_m": 493.0,
   "midpoint_distance_m": 492.0,
   "start_elevation_m": 76.10986463790137,
   "end_elevation_m": 77.04251753616276,
   "start_xy": [
    223068.7513951047,
    51730.35572007901
   ],
   "end_xy": [
    223070.61626259543,
    51731.02649191296
   ]
  },
  "max_3m": {
   "gradient_pct": 38.471471003701296,
   "start_distance_m": 125.0,
   "end_distance_m": 128.0,
   "midpoint_distance_m": 126.5,
   "start_elevation_m": 29.841662750005877,
   "end_elevation_m": 30.995806880116916,
   "start_xy": [
    222733.83735330787,
    51659.57004599815
   ],
   "end_xy": [
    222736.80666312575,
    51659.99806376112
   ]
  }
 },
 "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": 0.006,
   "windows_resited": [
    2.0,
    10.0,
    25.0,
    50.0
   ],
   "windows_unresolved": []
  },
  "placement_suppression": {
   "masked_fraction": 0.033,
   "windows_resited": [
    2.0,
    3.0,
    5.0,
    10.0,
    20.0,
    25.0
   ],
   "windows_unresolved": []
  },
  "overhead_obstruction": {
   "obstruction_threshold_m": 2.0,
   "obstructed_fraction": 0.058,
   "obstruction_max_height_m": 6.68,
   "flagged_windows_m": [
    10,
    20,
    25
   ]
  },
  "excluded_ranges_m": [
   [
    40.0,
    70.0
   ]
  ],
  "review": [],
  "extent": [
   "may_start_earlier"
  ]
 },
 "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/SX2050.tif"
  ],
  "calculated_at": "2026-08-31T05:48:18+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",
  "run_id": "placement-mask-260831",
  "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": [
   "SX2050.tif"
  ],
  "route_summit_trim_m": 145.5,
  "route_summit_trim_loss_m": 10.0,
  "climb_origin": "discovered",
  "naming_note": "auto-named from gazetteer (hypothesis, unreviewed); discovered as 'Discovered lane (50.3392, -4.4859)'",
  "license": "ODbL-1.0",
  "license_url": "https://howsteep.org/licensing.html"
 },
 "area": {
  "place": "Carey Park",
  "county": "Cornwall"
 }
}