{
  "schema": "plazaic.lunar-surface-provenance.v1",
  "imagery": {
    "title": "NASA SVS CGI Moon Kit natural-color texture / former LRC globe",
    "runtimeAsset": "../moon-texture.jpg",
    "runtimeDimensions": [
      2048,
      1024
    ],
    "sha256": "f7130a1822681fa7512d7dcfd40db8c10b9ba4f06777910348698260ed7a2170",
    "sourceUrl": "https://svs.gsfc.nasa.gov/4720/",
    "measurement": "LROC-derived natural-color visualization texture; polar coverage filled by the source visualization producer.",
    "processing": "Existing LRC image bytes retained unchanged. Gamma-aware directional lighting applied in the viewer.",
    "limitations": "Prepared for visualization, with source exposure/white-balance adjustments, polar fill and gap inpainting. Not used to calculate numerical abundances."
  },
  "elevation": {
    "title": "LOLA global lunar elevation: 4 pixels/degree retained-sample atlas grid",
    "sourceProductId": "LDEM_16",
    "sourceProductVersion": "V3.1",
    "sourceDataSetId": "LRO-L-LOLA-4-GDR-V1.0",
    "mission": "Lunar Reconnaissance Orbiter (LRO)",
    "instrument": "Lunar Orbiter Laser Altimeter (LOLA)",
    "producer": "NASA Goddard Space Flight Center / LRO_LOLA_TEAM",
    "producerFullName": "David E.Smith",
    "productCreationDate": "2019-03-15",
    "sourceMeasurementTimeRange": [
      "2009-07-13T17:33:17",
      "2016-11-29T05:48:19"
    ],
    "sourceUrl": "https://pds-geosciences.wustl.edu/lro/lro-l-lola-3-rdr-v1/lrolol_1xxx/data/lola_gdr/cylindrical/img/ldem_16.img",
    "sourceLabelUrl": "https://pds-geosciences.wustl.edu/lro/lro-l-lola-3-rdr-v1/lrolol_1xxx/data/lola_gdr/cylindrical/img/ldem_16.lbl",
    "verifiedMirrorUrl": "https://imbrium.mit.edu/DATA/LOLA_GDR/CYLINDRICAL/IMG/LDEM_16.IMG",
    "archiveDocumentationUrl": "https://pds-geosciences.wustl.edu/lro/lro-l-lola-3-rdr-v1/lrolol_1xxx/document/archsis.htm",
    "credit": "NASA/GSFC,LOLA Science Team;Planetary Data System Geosciences Node",
    "coordinateSystem": "BODY-FIXED ROTATING,MEAN EARTH/POLAR AXIS OF DE421",
    "latitudeConvention": "planetocentric,north-positive",
    "longitudeConvention": "east-positive,−180to180degrees",
    "mapProjection": "Simple Cylindrical (equirectangular)",
    "registration": "pixel-centred",
    "width": 1440,
    "height": 720,
    "pixelsPerDegree": 4,
    "degreesPerPixel": 0.25,
    "boundsDegrees": {
      "north": 90,
      "south": -90,
      "west": -180,
      "east": 180
    },
    "firstPixelCentreDegrees": {
      "latitude": 89.875,
      "longitudeEast": -179.875
    },
    "lastPixelCentreDegrees": {
      "latitude": -89.875,
      "longitudeEast": 179.875
    },
    "storage": "Row-major signed Int16, little-endian; rows north to south; columns west to east; no header.",
    "valueUnitMetres": 0.5,
    "heightFormula": "elevationMetres=DN*0.5;radiusMetres=1737400+DN*0.5",
    "elevationDatum": "Sphere of radius 1737400 m relative to the lunar centre of mass; not a geoid/equipotential.",
    "datumRadiusMetres": 1737400,
    "noDataValue": null,
    "sourceNoData": "No nodata/special-pixel sentinel is declared in the published label. All raster cells are populated; neither source nor export contains −32768.",
    "noDataPixelCount": 0,
    "validPixelFraction": 1,
    "publishedGridInterpretation": "Published gridded altimetry product: each source pixel represents a mean, scaled and interpolated where necessary. Complete grid coverage does not imply a direct laser return in every pixel.",
    "sourceKnownLimitations": [
      "The label notes possible edge artifacts at 45° latitude-band boundaries.",
      "Original LDEM_16 spacing is 1895.21 m in latitude; this retained 4 ppd grid has nominal 7580.84 m latitudinal spacing.",
      "The label lists extrema −18150..21580 DN; the actual pixel-registered numeric IMG spans −17963..21371 DN. Both official archives deliver identical bytes.",
      "This global atlas grid does not supply metre-scale site engineering terrain."
    ],
    "processing": "Shift original 0–360° longitude columns by 180°. At 4 ppd target pixel centres, use the nearest 16 ppd centres with a consistent southeast tie choice: retain source indices 4*row+2 and 4*column+2. No interpolation, averaging or noise added to elevation values.",
    "nearestCentreTieOffsetsDegrees": {
      "sampleLatitudeMinusTargetLatitude": -0.03125,
      "sampleLongitudeMinusTargetLongitude": 0.03125
    },
    "firstRetainedSourceCentreDegrees": {
      "latitude": 89.84375,
      "longitudeEast": -179.84375
    },
    "sourceWidth": 5760,
    "sourceHeight": 2880,
    "sourcePixelsPerDegree": 16,
    "sourceLabelExtremaDN": [
      -18150,
      21580
    ],
    "downloadedSourceExtremaDN": [
      -17963,
      21371
    ],
    "resamplingOfPublishedMeasuredDEM": true,
    "proceduralRelief": false,
    "minimumElevationMetres": -8865.5,
    "maximumElevationMetres": 10524.5,
    "minimumLocationApprox": {
      "latitude": -70.375,
      "longitudeEast": -172.375
    },
    "maximumLocationApprox": {
      "latitude": 5.375,
      "longitudeEast": -158.625
    },
    "rawByteCount": 2073600,
    "sourceSha256": "a511e40d7a3ea3275945b4da2a1df377133264fab0be94b7434b1cf8907254cb",
    "verifiedMirrorSha256": "a511e40d7a3ea3275945b4da2a1df377133264fab0be94b7434b1cf8907254cb",
    "sourceLabelSha256": "9aef29463ccc6ed3a3fbe0df3ecd830a99c69e16b564f455507dee2697096579",
    "exportSha256": "460d0f1c02d9c4a747f2cfa1d53be79a6da6ae9281bf69776afe207569036252",
    "runtimeSamplingNotes": [
      "Longitude wraps periodically; bilinear sampling should wrap columns at the 180° seam.",
      "Source and destination grids sample pixel centres, not exact poles. Use one consistent estimated height for a collapsed pole vertex (e.g. nearest-row mean).",
      "Destination bilinear coordinate formula: indexX=(longitudeEast+180)*4−0.5, indexY=(90−latitude)*4−0.5.",
      "DN values preserve 0.5 m quantization; this quantization is not a measure of elevation accuracy."
    ]
  },
  "rendering": {
    "meshCells": [
      720,
      360
    ],
    "degreesPerCell": 0.5,
    "elevationReadout": "bilinear retained4ppd pixel-centred DEM; longitude wrap, latitude clamp, collapsed pole row mean",
    "verticalExaggerationOptions": [
      1,
      5,
      10
    ],
    "initialVerticalExaggeration": 1,
    "initialTerrainEnabled": false,
    "heightDisplacement": "radius=1+elevation_metres*vertical_exaggeration/1737400",
    "abundanceRGB": "unchanged per-source palette, unshaded on relief; graticule remains optional",
    "imageryLighting": "Former LRC response: normalized view direction [-.55,.45,.8], .13+1.02*pow(max(incidence,0),.7), gamma 2.2; imagery only.",
    "gpuPickingQuantizationDegrees": {
      "longitude": 0.005493247882810712,
      "latitude": 0.002746623941405356
    },
    "maxTerrainRenderPixels": [
      1024,
      1024
    ],
    "sourceMaskPolicy": "Source specials and nonfinite imagery values mask alpha; missing DEM values omit triangle and return unavailable; dark camera pixels are valid. Actual delivered products contain zero unavailable samples. Abundance masks remain independent."
  },
  "preservation": {
    "baselineSiteVersion": 83,
    "embeddedPayloadSha256": "cae57db29e4bbcf3cad4dadca31d8a6346deeb5904fbc69af44fec882ab290f7",
    "placeRecords": 162,
    "unchanged": "Abundance fields, synthesized masks, Preview/Interpolation embedded pixels, annotation records, sample/export/import numerical behavior; startup Approximation, black→teal endpoints, normalization off.",
    "returnedSamples": "11 sites and all six-oxide values retained verbatim from former LRC."
  },
  "archivedMorphologicalImagery": {
    "mission": "Lunar Reconnaissance Orbiter (LRO)",
    "instrument": "Lunar Reconnaissance Orbiter Camera (LROC), Wide Angle Camera (WAC)",
    "measurement": "Camera imagery, monochrome 643 nm band (23 nm bandwidth); not a DEM, not radar.",
    "dataset": "LRO-L-LROC-5-RDR-V1.0 / WAC Global Morphologic Map",
    "product": "WAC_GLOBAL_E000N0000_016P",
    "productVersion": "v1.3",
    "producer": "Arizona State University / LRO LROC Team",
    "sourceStartTime": "2009-11-07T03:02:36",
    "sourceStopTime": "2011-01-31T18:06:02",
    "productCreationTime": "2015-07-28T02:33:20",
    "sourceDimensions": [
      5760,
      2880
    ],
    "sourcePixelsPerDegree": 16,
    "sourceMetersPerPixelAtEquator": 1895.2094015093,
    "nativeRegionalMosaicMetersPerPixel": 100,
    "runtimeDimensions": [
      4096,
      2048
    ],
    "runtimePixelsPerDegree": 11.377777777777778,
    "runtimeMetersPerPixelAtEquator": 2665.138220872513,
    "coverage": {
      "latitude": [
        90,
        -90
      ],
      "longitude": [
        -180,
        180
      ],
      "rowOrder": "north to south",
      "columnOrder": "west to east"
    },
    "coordinateSystem": "Planetocentric latitude, east-positive longitude; near-side/0° longitude at horizontal image center; equirectangular projection, center lat/lon 0°/0°.",
    "mapReferenceSphereMeters": 1737400,
    "pixelCenters": {
      "sourceLon": "-180 + (x+0.5)/16 degrees",
      "sourceLat": "90 - (y+0.5)/16 degrees",
      "runtimeLon": "-180 + (x+0.5)*360/4096 degrees",
      "runtimeLat": "90 - (y+0.5)*180/2048 degrees"
    },
    "sourceProcessing": "Official mosaic of >15,000 WAC images; projected using GLD100 at low/mid latitudes and LOLA shape model at 80–90°; improved geometric camera model and LOLA/GRAIL ephemeris; Hapke photometric correction to reduce seam brightness discrepancies. Original dataset contains mixed illumination and high-incidence shadows (53–70° equatorial incidence).",
    "localProcessing": "Retain official LROC 8-bit browse GeoTIFF brightness stretch. Area/BOX downsample 5760×2880 to 4096×2048 (and 2048×1024 fallback); encode RGBA PNG. No inpainting, colorization, procedural relief, invented imagery, or polar substitution. The source GeoTIFF brightness mapping is retained verbatim before downsampling; its display stretch is not newly estimated from source radiance. It is a visualization stretch, and source radiance is not claimed as a quantitative readout.",
    "maskProcessing": "Actual mask from original float32 PDS IMG: PDS special/null codes FF7FFFFB..FF7FFFFF and nonfinite values. No such samples occur in this 16 ppd product; alpha is therefore 255 throughout. GeoTIFF tag nodata=0 is not used as a source coverage mask because browse-zero pixels correspond to valid low/negative photometrically corrected source radiances ≤0.005. Such dark source samples remain genuine black camera pixels, not transparent.",
    "sourceValidSamples": 16588800,
    "sourceInvalidSamples": 0,
    "browseBlackPixels": 1379263,
    "limitations": "This is a photometrically processed, reduced-resolution camera mosaic rather than a simultaneous lunar photograph or calibrated abundance product. Deep/polar shadows remain black or poorly illuminated. The gridded 16 ppd product has no null pixels; this does not claim that individual permanent-shadow locations were directly illuminated or every 100 m source cell was observed. Original image illumination can remain visible when applying globe relief lighting. No source pole replacement was added locally.",
    "sourceUrls": {
      "page": "https://data.lroc.im-ldi.com/lroc/view_rdr/WAC_GLOBAL",
      "productPage": "https://data.lroc.im-ldi.com/lroc/view_rdr_product/WAC_GLOBAL_E000N0000_016P",
      "originalImg": "https://pds.mcp.nasa.gov/data/store/img/lunar_reconnaissance_orbiter/pds4/lroc/lro-l-lroc-5-rdr/LROLRC_2001/DATA/BDR/WAC_GLOBAL/WAC_GLOBAL_E000N0000_016P.IMG",
      "browseTif": "https://pds.mcp.nasa.gov/data/store/img/lunar_reconnaissance_orbiter/pds4/lroc/lro-l-lroc-5-rdr/LROLRC_2001/EXTRAS/BROWSE/WAC_GLOBAL/WAC_GLOBAL_E000N0000_016P.TIF",
      "readme": "https://pds.mcp.nasa.gov/data/store/img/lunar_reconnaissance_orbiter/pds4/lroc/lro-l-lroc-5-rdr/LROLRC_2001/DATA/BDR/WAC_GLOBAL/WAC_GLOBAL_README.TXT"
    },
    "credit": "NASA/GSFC/Arizona State University / LROC Team",
    "checksums": {
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      "WAC_GLOBAL_README.TXT": {
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      "lroc-wac-global-4k.png": {
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    "verification": {
      "sourceMaskVsBrowseZero": "Browse zeros have actual finite source data; verified no PDS special/null samples and no nonfinite floats.",
      "finiteSourceRadianceRange": [
        -0.07837105542421341,
        0.5991924405097961
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      "landmarkSamples": [
        {
          "label": "Near-side equator",
          "lat": 0,
          "lon": 0,
          "sourceX": 2880,
          "sourceY": 1440,
          "sourceRadiance": 0.028551872819662094,
          "sourceBrowseGray": 38
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        {
          "label": "Tycho",
          "lat": -43.31,
          "lon": -11.36,
          "sourceX": 2698,
          "sourceY": 2132,
          "sourceRadiance": 0.06618265807628632,
          "sourceBrowseGray": 97
        },
        {
          "label": "Copernicus",
          "lat": 9.62,
          "lon": -20.08,
          "sourceX": 2558,
          "sourceY": 1286,
          "sourceRadiance": 0.07361280918121338,
          "sourceBrowseGray": 108
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        {
          "label": "Eratosthenes",
          "lat": 14.47,
          "lon": -11.32,
          "sourceX": 2698,
          "sourceY": 1208,
          "sourceRadiance": 0.01515156589448452,
          "sourceBrowseGray": 17
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        {
          "label": "Plato",
          "lat": 51.62,
          "lon": -9.38,
          "sourceX": 2729,
          "sourceY": 614,
          "sourceRadiance": 0.02540844865143299,
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        },
        {
          "label": "Apollo 11",
          "lat": 0.674,
          "lon": 23.473,
          "sourceX": 3255,
          "sourceY": 1429,
          "sourceRadiance": 0.022014079615473747,
          "sourceBrowseGray": 28
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        {
          "label": "Orientale",
          "lat": -23.82,
          "lon": -77.32,
          "sourceX": 1642,
          "sourceY": 1821,
          "sourceRadiance": 0.04433733969926834,
          "sourceBrowseGray": 62
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      ],
      "webRetrievalLimitation": "Official PDS LROC URLs redirect to pds.mcp.nasa.gov; web retrieval could not follow that host, but supported executor HTTP downloads succeeded from the authoritative redirected URLs.",
      "runtimeMaskAlpha": "Decoded RGBA pixels all alpha=255 (actual source no-data count is zero).",
      "geographicAlignment": "PDS planetocentric/east-positive label, GeoTIFF sphere1737400m and tiepoint −5458203.0763469,+2729101.5381735m match ±180°,±90° edges. Known-location brightness samples use source floor((lon+180)*16), floor((90−lat)*16). Runtime BOX image retains those exact edges and north-to-south order; center pixels at half a pixel from edges."
    },
    "sourceBrowseStretch": {
      "classification": "Exact transfer function inferred from all original float32 source / official 8-bit GeoTIFF pixel pairs; not claimed as a quoted published parameter table.",
      "sourceRadianceKnots": [
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      "intermediateDisplayDNKnots": [
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      "mapping": "For source radiance f < 0.005, gray=0. Otherwise s=1+(f−0.005)*221/0.141 for f≤0.146, or s=222+(f−0.146)*33/0.094 for f>0.146. gray=clamp(floor(1+(s−1)*253/254+0.5),1,254), with double-precision computation. Source GeoTIFF retained verbatim before downsampling.",
      "blackThreshold": 0.005,
      "whiteInputKnot": 0.24,
      "maximumDisplayGray": 254,
      "validatedPixels": 16588800,
      "mismatchedPixels": 0,
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}