{
  "revision": "2026-09-18-environment-relief-v3",
  "layout": {
    "columns": 3,
    "rows": 2,
    "tileWidth": 2048,
    "tileHeight": 1024,
    "registration": "north to south, west to east"
  },
  "layers": [
    {
      "id": "magnetic",
      "classification": "fixed-date model",
      "source": "WMM2025",
      "validTime": "2026-09-13T00:00:00Z",
      "heightAboveWGS84Meters": 4000,
      "sourceManifest": "/spacetime-magnetic/v1/manifest.json",
      "colorSourceResolution": [
        512,
        256
      ],
      "presentationResize": "Lanczos resampling of unchanged prior plate; no new source detail."
    },
    {
      "id": "weather",
      "classification": "historical reference",
      "source": "NASA historical cloud-only mask",
      "live": false,
      "weathernextConnected": false,
      "colorSourceResolution": [
        512,
        256
      ],
      "presentationResize": "Lanczos resampling of unchanged prior plate; no new source detail."
    },
    {
      "id": "elevation",
      "classification": "reference relief",
      "source": "NOAA ETOPO 2022",
      "sourceManifest": "/spacetime-environment/2026-09-18-v3/manifest.json",
      "colorSourceResolution": [
        2048,
        1024
      ],
      "palette": [
        {
          "meters": 0,
          "color": "#496753"
        },
        {
          "meters": 200,
          "color": "#5d8060"
        },
        {
          "meters": 1000,
          "color": "#87956b"
        },
        {
          "meters": 2000,
          "color": "#ab9e75"
        },
        {
          "meters": 4000,
          "color": "#b1977e"
        },
        {
          "meters": 6000,
          "color": "#dbd5c4"
        },
        {
          "meters": 9000,
          "color": "#f4f3e8"
        }
      ],
      "shading": "Source-derived multiscale cartographic relief; not physical illumination"
    },
    {
      "id": "rf",
      "classification": "illustrative",
      "measuredFeed": false,
      "meaning": "authored chromatic signal-pattern study; no RF observations, strength, coverage or inference",
      "colorSourceResolution": [
        512,
        256
      ],
      "presentationResize": "Lanczos resampling of unchanged prior plate; no new source detail."
    },
    {
      "id": "currents",
      "classification": "illustrative",
      "measuredFeed": false,
      "meaning": "authored flow-pattern study on sourced ocean mask; no measured current vectors or speed",
      "colorSourceResolution": [
        512,
        256
      ],
      "presentationResize": "Lanczos resampling of unchanged prior plate; no new source detail."
    },
    {
      "id": "bathymetry",
      "classification": "reference relief",
      "source": "NOAA ETOPO 2022",
      "sourceManifest": "/spacetime-environment/2026-09-18-v3/manifest.json",
      "colorSourceResolution": [
        2048,
        1024
      ],
      "palette": [
        {
          "meters": 0,
          "color": "#b3d6c6"
        },
        {
          "meters": 200,
          "color": "#74b8ae"
        },
        {
          "meters": 1000,
          "color": "#3b8798"
        },
        {
          "meters": 3000,
          "color": "#1c4f71"
        },
        {
          "meters": 6000,
          "color": "#0c2341"
        },
        {
          "meters": 11000,
          "color": "#040c1d"
        }
      ],
      "shading": "Source-derived multiscale cartographic relief; not physical illumination"
    }
  ],
  "sourceHashes": {
    "magnetic": {
      "path": "/spacetime-magnetic/v1/wmm2025-intensity.png",
      "sha256": "725cf9c3f935d81dd6fce6a165663536efd91b47751e45f947fb63c642d6c2c8"
    },
    "clouds": {
      "path": "/earth-surface/v1/nasa-cloud-mask-1024.webp",
      "sha256": "4a95faeee792f3ba698b9caa9f7e4b770337df60eb8ce29825538c44b974b723"
    },
    "terrain": {
      "path": "/spacetime-magnetic/terrain-v2/etopo2022-512.i16",
      "sha256": "b4bf6a9a561f9804e48e73b7abb601145894806a7be2c7eaf2ba338508e9ea48"
    },
    "terrainHighResolution": {
      "sha256": "9d27d4b8ea8e76977e2988bca667d7c8fa68b927355feffcddd6b4875a7fd08e",
      "sourceURL": "https://www.ngdc.noaa.gov/mgg/global/relief/ETOPO2022/data/60s/60s_surface_elev_gtif/ETOPO_2022_v1_60s_N90W180_surface.tif",
      "originalWidth": 21600,
      "originalHeight": 10800,
      "verticalReference": "EGM2008 geoid",
      "derivation": "Bilinear downsampling directly from original 60 arc-second ETOPO 2022 surface grid to 2048 by 1024; colors applied after downsampling.",
      "derivedGridSHA256": "a9629bf40e8e2b1502a7432aaee3a00516f9c52c55b9771f59174d5d2c4cebb1"
    }
  },
  "asset": {
    "path": "/spacetime-environment/2026-09-18-v2/layers.webp",
    "sha256": "e3c40ef948330657d57db7775436cb9965934d4712eb21c5cb4523cae860b85b"
  },
  "limits": [
    "Reference dates do not change with the cinematic clock.",
    "Color transitions and relief shading are authored presentation, not new field values.",
    "Bathymetry is a color layer. Ocean geometry stays at sea level.",
    "No current-weather, RF, ocean-current, navigation-integrity or SLA-compliance claim.",
    "Terrain geometry remains existing 512 by 256 reference grid; this update increases terrain and bathymetry color detail only.",
    "Magnetic, weather, RF and currents source detail is unchanged.",
    "Shading and contours are cartographic display, not additional measurements.",
    "Elevation sign separates palettes; zero elevation is not an independent coastline.",
    "Below-sea-level land can appear in the depth palette; no ocean/land mask is claimed.",
    "Mesh remains 512 x 256 reference with 24x land relief and sea-level ocean geometry.",
    "Palette legend is unshaded; relief shading changes luminance, not source values."
  ],
  "reliefDerivation": {
    "revision": "2026-09-18-relief-v3",
    "sourceGrid": {
      "sourceSHA256": "9d27d4b8ea8e76977e2988bca667d7c8fa68b927355feffcddd6b4875a7fd08e",
      "sourceFullRangeMeters": [
        -10752.08203125,
        8157.3564453125
      ],
      "sourceNoDataPresent": false,
      "gridShape": [
        1024,
        2048
      ],
      "derivation": "Pillow bilinear resize of original float TIFF; no numeric values inferred from color",
      "rangeMeters": [
        -9715.6796875,
        6133.5107421875
      ],
      "gridSHA256": "a9629bf40e8e2b1502a7432aaee3a00516f9c52c55b9771f59174d5d2c4cebb1"
    },
    "previousAtlasSHA256": "e3c40ef948330657d57db7775436cb9965934d4712eb21c5cb4523cae860b85b",
    "atlasSHA256": "2e5d069b1d0b6b52a19f692b63c8cb9189c71f8cd8a36515e581885663bef7ab",
    "atlasBytes": 6977384,
    "reliefSHA256": "ec8ca29f3c7b5737d320e9796d52206232749636ec9ecd757e6fdb4ab8fa7a32",
    "reliefBytes": 2325730,
    "generatorSHA256": "f55073fab70c4c1ecdce0f7c2e6c11889343c924e7579a40547ae24dbac705c2",
    "palettes": {
      "elevation": [
        {
          "meters": 0,
          "color": "#496753"
        },
        {
          "meters": 200,
          "color": "#5d8060"
        },
        {
          "meters": 1000,
          "color": "#87956b"
        },
        {
          "meters": 2000,
          "color": "#ab9e75"
        },
        {
          "meters": 4000,
          "color": "#b1977e"
        },
        {
          "meters": 6000,
          "color": "#dbd5c4"
        },
        {
          "meters": 9000,
          "color": "#f4f3e8"
        }
      ],
      "bathymetry": [
        {
          "meters": 0,
          "color": "#b3d6c6"
        },
        {
          "meters": 200,
          "color": "#74b8ae"
        },
        {
          "meters": 1000,
          "color": "#3b8798"
        },
        {
          "meters": 3000,
          "color": "#1c4f71"
        },
        {
          "meters": 6000,
          "color": "#0c2341"
        },
        {
          "meters": 11000,
          "color": "#040c1d"
        }
      ]
    },
    "preservedDecodedTileSHA256": {
      "0": "b55432f38fd2b8c13ac1ef895126db37ac2b0912bad095c5746c2ad017a60a30",
      "1": "be9287539a9e07394dc2370aab2b0af8b0bf57d6a3355be9686803a622818613",
      "3": "12ec6bb2166096985963110d5c309c3995d5f52b6ef54eedf314745d016feb1a",
      "4": "0cef0aaf694ef6a8b8da6cb8c6913c2be7c73cdacc328687e2d3e67f7980d269"
    },
    "shading": {
      "lights": "72% northwest, 18% northeast, 10% overhead",
      "terrainGradientExaggeration": [
        24,
        36
      ],
      "bathymetryGradientExaggeration": [
        36,
        54
      ],
      "multiScale": "original grid plus 3x3 mean",
      "latitudeCosineFloor": 0.15,
      "longitudeDerivative": "periodic central difference",
      "latitudeDerivative": "central difference; one-sided edge",
      "bathymetryContourMeters": [
        200,
        1000,
        2000,
        3000,
        4000,
        5000,
        6000,
        8000
      ]
    },
    "limits": [
      "Shading and contours are cartographic display, not additional measurements.",
      "Elevation sign separates palettes; zero elevation is not an independent coastline.",
      "Below-sea-level land can appear in the depth palette; no ocean/land mask is claimed.",
      "Mesh remains 512 x 256 reference with 24x land relief and sea-level ocean geometry.",
      "Palette legend is unshaded; relief shading changes luminance, not source values."
    ]
  },
  "reliefAsset": {
    "path": "/spacetime-environment/2026-09-18-v3/relief.webp",
    "sha256": "ec8ca29f3c7b5737d320e9796d52206232749636ec9ecd757e6fdb4ab8fa7a32",
    "bytes": 2325730,
    "encoding": "lossless WebP",
    "layout": {
      "columns": 2,
      "rows": 1,
      "tileWidth": 2048,
      "tileHeight": 1024,
      "layers": [
        "elevation",
        "bathymetry"
      ]
    },
    "load": "Near the environmental section, alongside the unchanged original atlas",
    "textureStorageBytes": 16777216,
    "mipmaps": false
  }
}