{ "id": "swamp-canyon", "name": "Swamp Canyon head", "group": "The southern transition", "center": [ -112.212, 37.5858 ], "width_m": 768, "surface_method": "classified-ground", "source_ids": [ "nps-swamp", "nps-pois", "gnis" ], "place_ids": [ "swamp-canyon" ], "theme": "A canyon beneath the canopy", "question": "How does the ground fall away from the rim?", "interaction": "section", "view_yaw": 1.2, "view_pitch": 1.12, "schema": 1, "kind": "landscape-study", "checked_at": "2026-10-02", "geometry_status": "Derived from source-classified ground returns; terrain study, not a closed rock scan", "coordinate_system": { "native_horizontal": "NAD83(2011) / UTM 12N (EPSG:6341)", "ept_horizontal": "WGS84 Pseudo-Mercator (EPSG:3857)", "export_horizontal": "WGS84 / UTM 12N (EPSG:32612)", "vertical": "NAVD88, Geoid12B; source heights retained", "units": "metres", "axes": "x east, y up from base_m, z south", "base_m": 2310, "center_utm": [ 392991.8657405012, 4160550.683755696 ], "bounds_utm": [ 392607.8657405012, 4160166.683755696, 393375.8657405012, 4160934.683755696 ], "bounds_wgs84": [ -112.21640469967524, 37.58229484849404, -112.20759570272925, 37.58930500034746 ], "vertical_exaggeration": 1, "transform_note": "EPT projection transformed with pyproj; no claim of survey-grade datum alignment. Centimetre export quantization is not source accuracy." }, "statistics": { "returns_in_crop": 20138585, "density_returns_per_m2": 34.143, "ground_returns": 5566561, "retained_returns": 5566561, "vegetation_candidate_returns": 7799072, "excluded_noise_or_other": 6691, "directly_observed_node_fraction": 0.9366566730883956, "interpolated_node_fraction": 0.028909180032602625, "unsupported_node_fraction": 0.034434146879001704, "isolated_high_cells_repaired": 2, "source_gap_node_fraction": 0.022643244455083995, "cliff_or_small_patch_omission_fraction": 0.01179090242391771, "maximum_3x3_relief_m": 12.0, "minimum_connected_patch_m2": 100.0, "maximum_nearest_fill_m": 3.0, "cell_m": 1.5, "distance_reference": "Distance between grid-node centers, not exact source-point XY.", "maximum_grid_bin_offset_m": 1.0606601717798212, "maximum_source_xy_distance_bound_m": 4.060660171779821, "source_heights_m": [ 2323.56005859375, 2535.739990234375 ], "surface_heights_m": [ 2323.6201171875, 2517.080078125 ], "intensity_display_percentiles": [ 1952.0, 13728.0 ], "vertical_surfaces": "Abrupt interpolated cliff nodes are omitted; directly sampled bins are retained. Connecting top-surface samples still does not measure a wall, undercut, window or unseen interior.", "surface_method": "classified-ground" }, "levels": [ { "file": "small.glb.gz", "bytes": 413340, "uncompressed_bytes": 1099996, "sha256": "34ef3d51b5304c72eaa490dd0396baaa3c3ce42773227ebc0bb19a4601bd61a5", "id": "small", "vertices": 16641, "triangles": 30494, "grid_nodes": 129, "spacing_m": 6.0, "degenerate_triangles": 0, "downward_triangles": 0 }, { "file": "balanced.glb.gz", "bytes": 1576662, "uncompressed_bytes": 4398672, "sha256": "1d6ca01346da667defcb6e81b21e43921f9dfa953cfbd8c87e8551db93a2df2f", "id": "balanced", "vertices": 66049, "triangles": 124220, "grid_nodes": 257, "spacing_m": 3.0, "degenerate_triangles": 0, "downward_triangles": 0 }, { "file": "detailed.glb.gz", "bytes": 6160365, "uncompressed_bytes": 17598752, "sha256": "99705b06dae593d97ff639be9414e2de3b3cb6f211adda42badbde4331a0e162", "id": "detailed", "vertices": 263169, "triangles": 501452, "grid_nodes": 513, "spacing_m": 1.5, "degenerate_triangles": 0, "downward_triangles": 0 } ], "returns": { "file": "returns.glb.gz", "bytes": 1243300, "uncompressed_bytes": 2881236, "sha256": "2e89e947bc6a36caa8d90b189cce6b7999c60d7e66af791176b454260808001b", "count": 120000, "sampling": "fixed seed 20261002, uniform without replacement from valid crop returns" }, "profiles": "profiles.json.gz", "coverage": { "image": "coverage.webp", "data": "coverage.json.gz", "nodes": 513, "orientation": "north up; west left" }, "camera": { "yaw": 1.2, "pitch": 1.12, "distance_m": 1536.0, "target": [ 0, 127.93994140625, 0 ], "limits": { "minimum_distance_widths": 1.35, "maximum_distance_widths": 4, "minimum_pitch_radians": 1.0, "maximum_pitch_radians": 1.55 }, "scope": "Above-terrain observation only; no ground-level camera or visitor-viewpoint equivalence." }, "bounds_local": [ [ -384.0, 13.6201171875, -384.0 ], [ 384.0, 207.080078125, 384.0 ] ], "source_dataset": { "id": "USGS_LPC_UT_Southern_QL1_2018_LAS_2019", "acquired": "2018-04-27 / 2018-07-29 project interval", "published": "2019-06-03", "url": "https://registry.opendata.aws/usgs-lidar/", "license": "US Government Public Domain", "credit": "Map services and data available from U.S. Geological Survey, National Geospatial Program." }, "processing": { "mesh": "Source class 2 ground only. Highest retained return per nearest grid node; nearest interpolation up to 3 m; isolated spikes exceeding all 8 neighbors by 6 m lowered to neighbor maximum. Interpolated nodes with more than 12 m relief across a 3x3 neighborhood and connected patches smaller than 100 m² are omitted. Directly sampled ground bins otherwise remain, including steep rims. Original returns are unchanged. No morphological closing.", "vegetation": "Source classes 3/4/5 plus low-intensity multiple echoes and low-intensity raised returns over nearby gentle classified ground are excluded. This is an imperfect heuristic, not a species/rock classifier.", "lighting": "Normals and static 12-direction terrain occlusion are derived; material color, studio lighting and display category colors are illustrative.", "detail": "Three nested node grids; no-data cells omitted at every LOD; low LOD can omit extra edge triangles to preserve holes." }, "limitations": [ "Hidden rock surfaces, undercuts and windows are not reconstructed.", "Abrupt interpolated cliff nodes are omitted; connections between directly sampled bins are derived facets, not measured wall surfaces.", "Ground classification can omit standing rock or retain classification errors; inspect the return view.", "NAIP is overhead imagery from a different year; it cannot supply photographic detail on vertical faces.", "The cut boundary is an editorial crop; there is no modeled geology beneath it.", "No route, current condition, erosion rate or collapse forecast is inferred." ], "posters": { "large": "poster.webp", "small": "poster-small.webp", "material": "aerial", "geometry_year": 2018, "imagery_year": 2024, "kind": "actual model render, not a ground photograph" }, "quality_status": "qualified-ground-terrain-with-visible-omissions", "editorial": { "lede": "Beyond the main amphitheater, wooded hollows become part of the view.", "body": "NPS describes Swamp Canyon as a transition from densely packed hoodoos to the cliffs and buttes of southern Bryce. This crop concentrates on the head of the canyon near the overlook. Its ground surface separates the shape of the slope from the canopy above it.", "lesson": "Move a west-to-east section down the crop. Higher ground breaks into hollows with different depths. These are profiles of the source-classified ground surface, not trail elevations, stream measurements or mapped rock layers.", "limit": "Only the overlook sector is included. The full canyon, its spring and downstream drainage are outside this bounded study. Ground classification may omit standing rock and still misses hidden cliff faces.", "caption": "The head of Swamp Canyon near the overlook, derived from the survey's classified-ground returns.", "comparison": "NPS describes wetter vegetation below the rim. The model does not map wetness, identify species or locate a spring." }, "sources": [ { "id": "nps-swamp", "title": "Swamp Canyon", "url": "https://www.nps.gov/places/000/swamp-canyon.htm", "publisher": "National Park Service", "date": "2026-08-15", "retrieved_at": "2026-10-02", "license": "Facts paraphrased and linked. Photograph rights recorded separately per image.", "supports": "Southern landscape transition, overlook identity and broader canyon context; no wetland or species mapping." }, { "id": "nps-pois", "title": "NPS Public Points of Interest", "url": "https://mapservices.nps.gov/arcgis/rest/services/NationalDatasets/NPS_Public_POIs/FeatureServer/0", "publisher": "National Park Service", "date": "dataset records have individual dates", "retrieved_at": "2026-10-02", "license": "NPS public geospatial data; no endorsement; agency source and accuracy fields preserved", "supports": "Mapped overlook positions; Hat Shop Hoodoos Viewpoint 9513. Accuracy is unknown, scaled or >=14 m for used records. Existing travel coordinates remain unchanged; similar names with different roles are not substituted." }, { "id": "gnis", "title": "Geographic Names — Landforms", "url": "https://carto.nationalmap.gov/arcgis/rest/services/geonames/MapServer/5", "publisher": "US Geological Survey", "date": null, "retrieved_at": "2026-10-02", "license": "US Government Public Domain; USGS National Map terms", "supports": "Independent named-feature locators, including Hat Shop 1441625, Farview 1441016, Piracy 1444459 and Corral Hollow 1439972. Points do not define a feature boundary. Valley records include multiple positions, not a trail polyline." } ], "imagery": { "publisher": "USDA Farm Service Agency / FPAC", "dataset": "National Agriculture Imagery Program (NAIP), Utah 2024", "retrieved_at": "2026-10-02T09:10:27.781711+00:00", "source_pixels_m": 0.6, "export_pixels": 1280, "export_pixel_m": 0.6, "crs": "EPSG:32612", "requested_bounds": [ 392607.8657405012, 4160166.683755696, 393375.8657405012, 4160934.683755696 ], "export_extent": { "xmin": 392607.8657405012, "ymin": 4160166.683755696, "xmax": 393375.8657405012, "ymax": 4160934.683755696, "spatialReference": { "wkid": 32612, "latestWkid": 32612 } }, "flight_dates": [ "2024-07-23" ], "images": [ { "OBJECTID": 195951, "Name": "m_3711231_nw_12_060_20240723", "Category": 1, "year_ts": 2024, "ST": "UT", "QQNAME": "3711231NW060", "QQDATE": 1721692800000, "iDate_ts": 1749744257170 } ], "catalog_url": "https://apps.geo.fpac.usda.gov/geo-imagery/rest/services/naip/conus_naip/ImageServer/query?f=json&geometry=%7B%22xmin%22%3A392607.8657405012%2C%22ymin%22%3A4160166.683755696%2C%22xmax%22%3A393375.8657405012%2C%22ymax%22%3A4160934.683755696%2C%22spatialReference%22%3A%7B%22wkid%22%3A32612%7D%7D&geometryType=esriGeometryEnvelope&inSR=32612&spatialRel=esriSpatialRelIntersects&outFields=%2A&returnGeometry=false&where=Category%3D1+AND+year_ts%3D2024", "export_url": "https://apps.geo.fpac.usda.gov/geo-imagery/rest/services/naip/conus_naip/ImageServer/exportImage?f=json&bbox=392607.8657405012%2C4160166.683755696%2C393375.8657405012%2C4160934.683755696&bboxSR=32612&imageSR=32612&size=1280%2C1280&format=png&pixelType=U8&interpolation=RSP_BilinearInterpolation&adjustAspectRatio=false&bandIds=0%2C1%2C2&mosaicRule=%7B%22mosaicMethod%22%3A%22esriMosaicLockRaster%22%2C%22lockRasterIds%22%3A%5B195951%5D%2C%22mosaicOperation%22%3A%22MT_FIRST%22%7D", "direct_image_url": "https://apps.geo.fpac.usda.gov/geo-imagery/rest/services/naip/conus_naip/ImageServer/exportImage?f=image&bbox=392607.8657405012%2C4160166.683755696%2C393375.8657405012%2C4160934.683755696&bboxSR=32612&imageSR=32612&size=1280%2C1280&format=png&pixelType=U8&interpolation=RSP_BilinearInterpolation&adjustAspectRatio=false&bandIds=0%2C1%2C2&mosaicRule=%7B%22mosaicMethod%22%3A%22esriMosaicLockRaster%22%2C%22lockRasterIds%22%3A%5B195951%5D%2C%22mosaicOperation%22%3A%22MT_FIRST%22%7D", "original_sha256": "50a847a1d8565e68ddcc0a0bc28729ab5bc9098a0c8ff98987de49f5a27df8ab", "license": "US Government Public Domain", "license_url": "https://catalog.data.gov/dataset/national-agriculture-imagery-program-naip-imagery", "processing": "Locked 2024 primary rasters, RGB bands 0/1/2, orthographic drape; bilinear export, WebP encoding. No invented detail.", "limitations": "Leaf-on aerial imagery draped on 2018 filtered topography; acquisition shadows, tree crowns, temporal differences and metre-scale registration error remain. Cliff faces stretch a top-down pixel; hidden walls are not photographed." }, "visual_review": { "checked_at": "2026-10-02", "views": [ "overview", "left oblique", "right oblique", "nearest allowed", "aerial", "north-up" ], "scope": "Above-terrain ground study only. Visible gaps remain; neither closed cliffs nor cap/neck fidelity is accepted.", "camera_minimum_pitch_degrees": 57.2957795, "camera_minimum_distance_widths": 1.35 } }