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 "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": {
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 "provenance": {
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  "calculated_at": "2026-08-24T21:40:38+00:00",
  "road_source": "OpenStreetMap (local PBF extract)",
  "road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
  "osm_pbf_path": "data/cache/pbf/massachusetts-260822.osm.pbf",
  "osm_snapshot": "2026-08-21T20:21:11Z",
  "run_id": "redo-ma-1-260824",
  "elevation_provider": "USGS 3DEP (The National Map)",
  "elevation_licence": "Public domain \u2014 USGS 3DEP 1 m DEM, courtesy of the U.S. Geological Survey",
  "elevation_dataset": "USGS 3DEP 1 m DEM, MA_Western_B24 (collected 2023-24)",
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  "notes": "Coarse pass: max 13.9% over 200 m (Terrain 50), gain 109.1 m over 3264 m way. EXTENDED by graph walk: +2 segment(s) at base, +3 at top (stop: base=no_descending_continuation, top=no_ascending_continuation; min_avg=2.0%). Review before adopting. DEDUPE: absorbed 2 overlapping proposal(s): discovered-lane-42-3877-72-7415, petticoat-hill-road-2 ADOPTED (NE wave 1, 2026-08-25): big-gain. Wales dials per PRODUCTION 'US ADOPTION DIALS'.",
  "canopy_check": "unavailable \u2014 no surface model (DSM or point cloud) registered for this coverage",
  "license": "ODbL-1.0",
  "license_url": "https://howsteep.org/licensing.html"
 },
 "area": {
  "place": "Williamsburg",
  "county": "Massachusetts"
 }
}