{
  "schemaVersion": 1,
  "id": "wulingyuan-region-v1",
  "name": {
    "zh-Hans": "武陵源真实区域地形数据",
    "en": "Wulingyuan real regional terrain data"
  },
  "status": "Data and offline CPU preview only; not integrated into the website or approved as a finished destination scene",
  "preparedAt": "2026-10-22T20:14:37.270918+00:00",
  "bounds": {
    "west": 110.4,
    "south": 29.28,
    "east": 110.56,
    "north": 29.44
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  "center": {
    "longitude": 110.48,
    "latitude": 29.36
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  "regionEvidence": [
    {
      "coordinates": [
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        29.33333
      ],
      "role": "UNESCO Wulingyuan heritage representative point only",
      "officialDMS": "N29 19 59.988 E110 30 0",
      "source": "https://whc.unesco.org/en/list/640/maps/",
      "note": "Not Yuanjiajie's individual attraction anchor, a pillar coordinate, a navigation point, or a polygon boundary."
    }
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  "extentRationale": "User-requested WGS84 crop 110.40..110.56 E and 29.28..29.44 N around Wulingyuan / intended Yuanjiajie regional context; crop is not the UNESCO heritage boundary. Exact Yuanjiajie attraction anchor remains unverified in primary coordinate evidence.",
  "yuanjiajieAnchor": null,
  "yuanjiajieEvidence": {
    "status": "Official relative position verified; precise coordinate still unverified",
    "description": "Hunan Department of Culture and Tourism places Yuanjiajie north of Shadao Gully, in the core Wulingyuan scenic area. No unsourced commercial point has been adopted.",
    "source": "https://whhlyt.hunan.gov.cn/whhlyt/english/Tourism/NationalForestParks/202205/t20220530_24762927.html"
  },
  "officialRegionalMaps": [
    "https://whc.unesco.org/document/104842",
    "https://whc.unesco.org/document/127713"
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    "metersPerDegreeLongitude": 97021.2051005596,
    "metersPerDegreeLatitude": 111319.49079327358,
    "widthMeters": 15523.392816089205,
    "depthMeters": 17811.11852692379,
    "axes": {
      "x": "east",
      "y": "up",
      "z": "south"
    },
    "formula": "x=(longitude-center.longitude)*metersPerDegreeLongitude; z=(center.latitude-latitude)*metersPerDegreeLatitude; y=sourceElevationMeters. Subtract one common base height for rendering; do not normalise tiles separately."
  },
  "elevation": {
    "encoding": "float32",
    "byteOrder": "little-endian",
    "unit": "metre",
    "crs": "EPSG:4326",
    "coordinateOrder": "longitude,latitude",
    "rowOrder": "north-to-south",
    "columnOrder": "west-to-east",
    "gridConvention": "Inclusive vertex grid: northwest and southeast vertices lie on exact bounds; no half-texel offset for heights.",
    "interpolation": "Bilinear interpolation of decoded source metres, no procedural height, no sharpening or per-tile normalisation",
    "verticalExaggeration": 1,
    "noData": null,
    "grids": [
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          "northSouth": 34.855417860907615
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        "minimumMeters": 306.1565246582031,
        "maximumMeters": 1261.4932861328125
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          "northSouth": 69.84752363499526
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        "minimumMeters": 308.0206298828125,
        "maximumMeters": 1258.6480712890625
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    "sourceZoom": 12,
    "sourceTilePixelSize": 256,
    "sourceGroundPixelMetersAtCenter": 33.30958732242723,
    "source": {
      "name": "Mapzen Terrain Tiles / Tilezen Joerd, AWS Open Data",
      "format": "Terrarium RGB PNG",
      "decode": "R*256+G+B/256-32768 metres",
      "registry": "https://registry.opendata.aws/terrain-tiles/",
      "sourceDocumentation": "https://github.com/tilezen/joerd/blob/master/docs/data-sources.md",
      "formatDocumentation": "https://github.com/tilezen/joerd/blob/master/docs/formats.md",
      "tiles": [
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          "x": 3304,
          "y": 1697,
          "url": "https://s3.amazonaws.com/elevation-tiles-prod/terrarium/12/3304/1697.png",
          "imagerySources": "srtm/N29E110.tif",
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          "url": "https://s3.amazonaws.com/elevation-tiles-prod/terrarium/12/3305/1697.png",
          "imagerySources": "srtm/N29E110.tif",
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          "y": 1698,
          "url": "https://s3.amazonaws.com/elevation-tiles-prod/terrarium/12/3304/1698.png",
          "imagerySources": "srtm/N29E110.tif",
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          "y": 1698,
          "url": "https://s3.amazonaws.com/elevation-tiles-prod/terrarium/12/3305/1698.png",
          "imagerySources": "srtm/N29E110.tif",
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          "x": 3304,
          "y": 1699,
          "url": "https://s3.amazonaws.com/elevation-tiles-prod/terrarium/12/3304/1699.png",
          "imagerySources": "srtm/N29E110.tif",
          "path": "source-terrarium/12-3304-1699.png",
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          "sha256": "837f35217f292d2acfbe2933e1f67382a4fb5bd9e70cbd4b4f1fc0f128e02555"
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          "y": 1699,
          "url": "https://s3.amazonaws.com/elevation-tiles-prod/terrarium/12/3305/1699.png",
          "imagerySources": "srtm/N29E110.tif, gmted/10N090E_20101117_gmted_mea075.tif",
          "path": "source-terrarium/12-3305-1699.png",
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          "sha256": "d388a1a46ccc06aee2ca28af175d8f7f6d5820f692b7e474afba4829229e70b1"
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    "sourceNativeResolution": "SRTM nominal one arc-second (about 30 m); Tilezen describes nominal quality as about 90 m. One source tile also lists GMTED2010 mea075 (7.5 arc-second, coarser fallback). Header provenance is tile-wide, not a per-output-pixel source mask. A z13 download would oversample these sources, not reveal individual pillars.",
    "sourceAcquisitionNote": "SRTM mission February 2000; GMTED2010 is a multi-source historical composite. Neither is a 2025 field survey, current scenery capture, or per-pillar photogrammetry.",
    "verticalDatum": "Predominantly SRTM: USGS describes WGS84 horizontal / EGM96 vertical datum, metre elevations. One Mapzen tile also lists GMTED2010. Exact composite per-pixel vertical datum not independently surveyed; preserve source metres. Not ellipsoidal or navigation-grade heights.",
    "officialSourceDefinition": "https://www.usgs.gov/centers/eros/science/usgs-eros-archive-digital-elevation-shuttle-radar-topography-mission-srtm-1/",
    "license": {
      "name": "Source-specific: SRTM and GMTED2010 USGS public-domain data; worldwide Mapzen collection is not blanket CC0",
      "url": "https://github.com/tilezen/joerd/blob/master/docs/attribution.md",
      "credit": "Terrain tiles: Mapzen / Tilezen. SRTM and GMTED2010 data courtesy of the U.S. Geological Survey."
    },
    "diagnosticPreviews": [
      {
        "path": "dem-hillshade.png",
        "classification": "DEM-gradient hillshade"
      },
      {
        "path": "dem-height-diagnostic.png",
        "classification": "Artificial height colour ramp, not satellite, forest classification, or scenery photograph"
      }
    ],
    "sampledReferences": [
      {
        "id": "wulingyuan-unesco",
        "coordinates": [
          110.5,
          29.33333
        ],
        "elevationMeters": 927.5142208739859
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    ]
  },
  "imagery": {
    "classification": "Real, historical Sentinel-2 L2A true-colour satellite image; not close-range scenery photography",
    "bounds": {
      "west": 110.4,
      "south": 29.28,
      "east": 110.56,
      "north": 29.44
    },
    "crs": "EPSG:4326",
    "coordinateOrder": "longitude,latitude",
    "rowOrder": "north-to-south",
    "columnOrder": "west-to-east",
    "width": 1024,
    "height": 1024,
    "transform": [
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      110.4,
      0.0,
      -0.00015625000000000014,
      29.44
    ],
    "pixelConvention": "Pixel-area grid: bounds are outer edges, samples at half-texel centres. Match DEM using its inclusive geographic bounds, not vertex index as a pixel centre.",
    "nativeSourcePixelMeters": 10,
    "readOverviewPixelMeters": 20,
    "outputApproximatePixelMeters": {
      "eastWest": 15.159563296962114,
      "northSouth": 17.393670436449014
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    "acquisitionDateTime": "2025-01-19T03:29:52.169000Z",
    "stacId": "S2A_49RDN_20250119_0_L2A",
    "sourceSun": {
      "azimuthDegreesClockwiseFromNorth": 156.768165477099,
      "elevationDegreesAboveHorizon": 36.8730386237001,
      "note": "Scene-level source STAC illumination, useful for avoiding contradictory new lighting; not a per-pixel relighting solution."
    },
    "stacItem": "https://earth-search.aws.element84.com/v1/collections/sentinel-2-l2a/items/S2A_49RDN_20250119_0_L2A",
    "sourceAsset": "https://sentinel-cogs.s3.us-west-2.amazonaws.com/sentinel-s2-l2a-cogs/49/R/DN/2025/1/S2A_49RDN_20250119_0_L2A/TCI.tif",
    "wholeTileCloudCoverPercent": 0.000478,
    "localCloudCoverPercent": null,
    "localCloudWarning": "STAC cloud percentage covers the whole approximately 100 km tile, not an independent local cloud measurement. Inspect crop before approving scenic use.",
    "coverageFraction": 1.0,
    "noDataPixels": 0,
    "sourceWindow": {
      "crs": "EPSG:32649",
      "readPixelMeters": [
        20.0,
        20.0
      ],
      "overviewIndex": 0,
      "shape": [
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        5490
      ],
      "window": {
        "columnOffset": 2086,
        "rowOffset": 2154,
        "width": 784,
        "height": 893
      },
      "clippedShape": [
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      ],
      "wholeSceneBytesNotDownloaded": 315010453
    },
    "master": {
      "path": "sentinel-2025-01-19-rgb.png",
      "bytes": 1839613,
      "sha256": "9a3fae5b3be47149b4e4b3d58dc1caec6b302a7ca9f4238ebe0116e0834d2117"
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    "runtime": {
      "path": "sentinel-2025-01-19-rgb.webp",
      "bytes": 285870,
      "sha256": "ec11da3d2b2ec74a8d68c38514cccf04469e29748de22d440d74f66254b5ed00"
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    "processing": {
      "bands": [
        "B04/red",
        "B03/green",
        "B02/blue"
      ],
      "providerScaling": "TCI visual asset already display-scaled by source provider",
      "resampling": "20 m COG overview, clipped in UTM49N then bilinearly reprojected to exact WGS84 bounds",
      "colorEdits": "None; no synthetic trees, recolour, snow, clouds, sharpening or generative fill",
      "mosaic": "Single item / single acquisition date"
    },
    "license": {
      "name": "Copernicus Sentinel Data legal notice: free, full and open access, adaptation and redistribution with source notice; not CC0",
      "url": "https://cds.climate.copernicus.eu/licences/ec-sentinel",
      "credit": "Contains modified Copernicus Sentinel data 2025",
      "provider": "Copernicus / ESA Sentinel-2; COG processed and hosted by Element84 / AWS Earth Search",
      "registry": "https://registry.opendata.aws/sentinel-2-l2a-cogs/"
    },
    "localSceneClassification": {
      "sourceAsset": "https://sentinel-cogs.s3.us-west-2.amazonaws.com/sentinel-s2-l2a-cogs/49/R/DN/2025/1/S2A_49RDN_20250119_0_L2A/SCL.tif",
      "asset": {
        "path": "sentinel-2025-01-19-scl.png",
        "bytes": 95779,
        "sha256": "80b45422cc45b164e8c83fe87666a16eb6d9855b19f3a1a524007d18657ebcc5"
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      "nativeSourcePixelMeters": 20,
      "resampling": "Nearest neighbour categorical values, no RGB edits or filling",
      "classes": [
        {
          "value": 0,
          "label": "No data",
          "pixels": 0,
          "fraction": 0.0
        },
        {
          "value": 1,
          "label": "Saturated or defective",
          "pixels": 0,
          "fraction": 0.0
        },
        {
          "value": 2,
          "label": "Topographic cast shadow",
          "pixels": 250047,
          "fraction": 0.2384634017944336
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        {
          "value": 3,
          "label": "Cloud shadow",
          "pixels": 0,
          "fraction": 0.0
        },
        {
          "value": 4,
          "label": "Vegetation",
          "pixels": 458887,
          "fraction": 0.43762874603271484
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        {
          "value": 5,
          "label": "Not vegetated",
          "pixels": 337798,
          "fraction": 0.32214927673339844
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        {
          "value": 6,
          "label": "Water",
          "pixels": 1844,
          "fraction": 0.001758575439453125
        },
        {
          "value": 7,
          "label": "Unclassified",
          "pixels": 0,
          "fraction": 0.0
        },
        {
          "value": 8,
          "label": "Cloud medium probability",
          "pixels": 0,
          "fraction": 0.0
        },
        {
          "value": 9,
          "label": "Cloud high probability",
          "pixels": 0,
          "fraction": 0.0
        },
        {
          "value": 10,
          "label": "Thin cirrus",
          "pixels": 0,
          "fraction": 0.0
        },
        {
          "value": 11,
          "label": "Snow or ice",
          "pixels": 0,
          "fraction": 0.0
        }
      ],
      "cloudClassFraction": 0.0,
      "snowOrIceClassFraction": 0.0,
      "definition": "https://sentiwiki.copernicus.eu/web/s2-processing#S2Processing-ClassificationMaskGeneration",
      "warning": "Source Sen2Cor algorithm classification, not independent field validation, detailed land cover, or proof that no haze exists."
    }
  },
  "imageryCandidates": [
    {
      "path": "imagery-candidates/S2A_49RDN_20250119_0_L2A.json",
      "bytes": 5732,
      "sha256": "898ed4d3a25308ae0b166f30fe1db95056ae0bb9d7d3dd38681b1f7f6a3d410c"
    },
    {
      "path": "imagery-candidates/S2B_49RDN_20250613_0_L2A.json",
      "bytes": 3157,
      "sha256": "3f5617efd52985ab9204545bda3fb8377140a5115b3d103997db41c9e2dff762"
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  ],
  "downloadBudget": {
    "limitBytes": 20000000,
    "actualRetainedSourceBodyBytes": 5463571,
    "measurement": "See acquisition-ledger.json; exact consumed HTTP bodies, excludes wire/header overhead",
    "price": 0
  },
  "limitations": [
    "Regional terrain only. Approximately 30 m source DEM smooths narrow sandstone pillars, cliff faces, overhangs and ravines; a 512 grid or higher zoom does not add survey detail.",
    "No claim of individual-pillar mapping, measured rock geometry, photogrammetry, current vegetation, current weather, or scene-ready AAA scenery.",
    "Can supply authentic large valley and ridge structure for a future scene. Close rock faces, coherent canopy and verified local landmarks still need separately prepared assets.",
    "DEM and Sentinel imagery have different historical acquisition dates and resolutions. Dated image shadows are baked into the colour; do not apply a contradictory strong sun.",
    "The diagnostic ramp and any future artistic augmentation must remain separately identified from real elevation and historical satellite RGB."
  ],
  "tooling": {
    "script": "scripts/prepare-zhangjiajie-region.py",
    "rasterio": "1.4.3",
    "gdal": "3.9.3"
  }
}