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"end_distance_m": 361.0, "midpoint_distance_m": 359.5, "start_elevation_m": 143.54965914848555, "end_elevation_m": 143.96716881239553, "start_xy": [ 241772.7998089563, 256986.44418770482 ], "end_xy": [ 241770.36563926103, 256984.69067183815 ] } }, "diagnostic_note": "Windows <=3 m are at raster-noise scale (roughly +/-2 pp 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": 0.064, "obstruction_max_height_m": 19.21, "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/wales/dtm_1m/wg_del_24_240254_20220120dtm.tif", "data/cache/wales/dtm_1m/wg_del_24_240255_20220120dtm.tif", "data/cache/wales/dtm_1m/wg_del_24_240256_20220120dtm.tif", "data/cache/wales/dtm_1m/wg_del_24_240257_20220120dtm.tif", "data/cache/wales/dtm_1m/wg_del_24_241254_20220120dtm.tif", "data/cache/wales/dtm_1m/wg_del_24_241255_20220120dtm.tif", "data/cache/wales/dtm_1m/wg_del_24_241256_20220120dtm.tif", "data/cache/wales/dtm_1m/wg_del_24_241257_20220120dtm.tif", "data/cache/wales/dtm_1m/wg_del_24_242254_20220120dtm.tif", "data/cache/wales/dtm_1m/wg_del_24_242255_20220120dtm.tif", "data/cache/wales/dtm_1m/wg_del_24_242256_20220120dtm.tif", "data/cache/wales/dtm_1m/wg_del_24_242257_20220120dtm.tif" ], "calculated_at": "2026-08-12T23:12:10+00:00", "road_source": "trunk-adopted-routes/discovered-lane-52-1809-4-3172.geojson", "elevation_provider": "Welsh Government", "elevation_dataset": "Welsh Government LiDAR 1m DTM (2020-2023)", "elevation_licence": "Open Government Licence v3 \u2014 \u00a9 Crown copyright Welsh Government", "elevation_catalogue_layer": "geonode:welsh_government_lidar_tile_catalogue_2020_2023", "elevation_tile_ids": [ "wg_del_24_240254_20220120dtm.tif", "wg_del_24_240255_20220120dtm.tif", "wg_del_24_240256_20220120dtm.tif", "wg_del_24_240257_20220120dtm.tif", "wg_del_24_241254_20220120dtm.tif", "wg_del_24_241255_20220120dtm.tif", "wg_del_24_241256_20220120dtm.tif", "wg_del_24_241257_20220120dtm.tif", "wg_del_24_242254_20220120dtm.tif", "wg_del_24_242255_20220120dtm.tif", "wg_del_24_242256_20220120dtm.tif", "wg_del_24_242257_20220120dtm.tif" ], "elevation_capture_dates": [ "20-01-2022" ], "climb_origin": "discovered", "notes": "Coarse pass: max 10.8% over 200 m (Terrain 50), gain 82.3 m over 2869 m way. EXTENDED by graph walk: +2 segment(s) at base, +4 at top (stop: base=no_descending_continuation, top=no_ascending_continuation; min_avg=2.0%). Review before adopting. ADOPTED (trunk sweep, Peter's on-sight verdict 2026-08-12): clean table, adopt-all. AUTO-NAMED from gazetteer (hypothesis, unreviewed): was 'Discovered lane (52.1809, -4.3172)'.", "naming_note": "auto-named from gazetteer (hypothesis, unreviewed); discovered as 'Discovered lane (52.1809, -4.3172)'" }, "area": { "place": "Pen-cae", "county": "Sir Ceredigion - Ceredigion" } }