{ "schemaVersion": 1, "id": "mexico-nature-parity-relief-v1", "purpose": "Neutral shaded elevation context behind the INEGI landform classification outlines.", "derivedBy": "Insight Journal offline processing; this hillshade is not an official INEGI classification.", "file": "relief.webp", "bytes": 61462, "sha256": "8494a6eceeea62633ad54c7a3447aa9e25466b6df071bd7d500a3baea428469f", "source": { "sourceUrl": "https://www.ncei.noaa.gov/products/etopo-global-relief-model", "downloadUrl": "https://www.ngdc.noaa.gov/mgg/global/relief/ETOPO2022/data/60s/60s_surface_elev_gtif/ETOPO_2022_v1_60s_N90W180_surface.tif", "sourceEdition": "ETOPO 2022 v1 60 arc-second surface", "sourceFile": "ETOPO_2022_v1_60s_N90W180_surface.tif", "sourceSha256": "9d27d4b8ea8e76977e2988bca667d7c8fa68b927355feffcddd6b4875a7fd08e", "sourceBytes": 465969062, "retrievedAt": "2026-10-02T06:22:13Z", "license": "CC0-1.0", "licenseUrl": "https://www.ncei.noaa.gov/metadata/geoportal/rest/metadata/item/gov.noaa.ngdc.mgg.dem%3Aetopo_2022/html", "userGuideUrl": "https://www.ngdc.noaa.gov/mgg/global/relief/ETOPO2022/docs/1.2%20ETOPO%202022%20User%20Guide.pdf", "citation": "NOAA National Centers for Environmental Information. 2022: ETOPO 2022 15 Arc-Second Global Relief Model. DOI:10.25921/fd45-gt74. Accessed 2026-10-02.", "horizontalCrs": "EPSG:4326", "verticalDatum": "EGM2008 geoid", "unit": "m", "editionNotObservationYear": true }, "decodedGrid": { "sourceSha256": "9d27d4b8ea8e76977e2988bca667d7c8fa68b927355feffcddd6b4875a7fd08e", "file": "mexico-etopo-window.f32", "sha256": "47e9c1792e653c05e94058b2b7311a18a7db38c094d47fb0f8a5acfef45c9743", "bytes": 9504000, "width": 1980, "height": 1200, "window": [ 3660, 3360, 5640, 4560 ], "origin": [ -119, 34 ], "resolution": [ 0.016666666666666666, -0.016666666666666666 ], "dtype": "float32-little-endian", "noData": -99999, "geoKeys": { "GTModelTypeGeoKey": 2, "GTRasterTypeGeoKey": 1, "GTCitationGeoKey": "WGS 84 + EGM2008 height", "GeographicTypeGeoKey": 4326, "VerticalCSTypeGeoKey": 3855 }, "method": "GeoTIFF.js 3.0.5 exact native window read; no resampling or integer casting", "verifiedAgainst": "mexico-water-v1/contours.source.json" }, "landClip": { "source": "Fuente: INEGI, Marco Geoestadistico, diciembre de 2025; 32 retained state geometries.", "sourceUrl": "https://gaia.inegi.org.mx/wscatgeo/v2/geo/mgee/", "documentation": "https://www.inegi.org.mx/servicios/catalogounico.html", "license": "INEGI Terminos de Libre Uso de la Informacion; attribution and transformation disclosure required.", "licenseUrl": "https://www.inegi.org.mx/inegi/terminos.html", "originalSourceSha256": "170c3ea5ff472f08ece97970dc90ad4ba8c6f503e33859655f315091c105cc91", "retainedGeometryFile": "src/data/atlas/mexico/geometry.json", "retainedGeometrySha256": "193f700c8741c2752561de077c781383dcc28a95244fb60726f591f8af011faa", "geometryIndexFile": "src/data/atlas/mexico/geometry-index.json", "geometryIndexSha256": "c18f61eb22816d9cb3b655df8a2aa71da2dcfc84b4bb4339308d0ea9d4d6689b", "method": "Project retained INEGI geographic state polygon vertices with the same GRS80 Lambert forward formula; union polygons; retain output pixel centres contained by that union. Alpha zero elsewhere." }, "displayFrame": { "width": 900, "height": 580, "viewBox": "0 0 900 580", "imagePlacement": { "x": 0, "y": 0, "width": 900, "height": 580, "preserveAspectRatio": "none" }, "projection": { "name": "INEGI Lambert Conformal Conic", "datum": "ITRF92", "ellipsoid": "GRS80", "semiMajorM": 6378137, "inverseFlattening": 298.257222101, "standardParallel1": 17.5, "standardParallel2": 29.5, "latitudeOrigin": 12, "centralMeridian": -102, "falseEastingM": 2500000, "falseNorthingM": 0 }, "boundsNative": [ 911292.029449366, 319149.06252919696, 4083063.0952772293, 2349614.87171421 ], "scalePixelsPerNativeMetre": 0.00025806886165215595, "leftPixels": 40.73232581027895, "topPixels": 28.0, "metresPerPixelInLambertPlane": 3874.934750353078, "cornersOrder": [ "top-left", "top-right", "bottom-right", "bottom-left" ], "frameCornersNative": [ [ 753456.9247044125, 2458113.0447240965 ], [ 4240898.200022183, 2458113.0447240965 ], [ 4240898.200022183, 210650.88951931102 ], [ 753456.9247044125, 210650.88951931102 ] ], "frameCornersLonLat": [ [ -120.60837078498076, 33.16425881431248 ], [ -83.45110248274294, 33.17077474263814 ], [ -86.09416672508411, 13.017717839780246 ], [ -117.95698415756823, 13.012123383493336 ] ], "pixelRegistration": "Cell centres at x+0.5,y+0.5 within the full SVG display frame.", "mapping": "x=left+(nativeX-minX)*scale; y=top+(maxY-nativeY)*scale; scale=min(844/(maxX-minX),524/(maxY-minY)).", "geographicNote": "Matches atlas-mexico-projection.mjs and its existing geographic rendering. No epoch-dependent ITRF92/WGS84 transformation or cadastral precision is asserted." }, "method": { "resampling": "Inverse exact display-frame Lambert mapping; bilinear interpolation of four valid native cell-centre float32 heights. No resampling of the cached native grid itself.", "noData": -99999, "missingData": "Nonfinite/NoData/out-of-window donors invalidate the sample. All five samples needed by the central derivative must be valid. No fill, extrapolation, synthetic terrain or contour-to-surface reconstruction.", "hillshade": "Lambert-plane east/north central finite differences of sampled EGM2008 metre heights, with a one-pixel source-sampled halo; dot product of normalized surface normal and directional light, clipped to [0,1].", "lightAzimuthDegreesClockwiseFromNorth": 315, "lightAltitudeDegrees": 45, "verticalExaggerationForDisplay": 5, "paperRgb": [ 245, 241, 220 ], "ambientFraction": 0.65, "darkeningFactor": 0.62, "tone": "gray=255*(0.65+0.35*hillshade); rgb=clip([245,241,220]-(255-gray)*0.62,0,255). Uses the US paper tone and neutral darkening factor from map/atlas/prepare_maplibre.py.", "encoding": "Lossless RGBA WebP; exact transparent RGB; transparent outside retained INEGI land." }, "checks": { "originalSourceHashMatches": true, "nativeGridHashMatches": true, "retainedBoundaryMatchesExistingContours": true, "outputPixelCount": 522000, "validLandPixelCount": 130103, "landPixelsWithoutSourceSupport": 0, "nonzeroAlphaOutsideLand": 0, "webpLosslessRoundTripExact": true, "lambertRoundTripMaxNativeMetres": 6.05359673500061e-09, "sampledLandHeightMinM": -364.4692386639753, "sampledLandHeightMaxM": 4715.923780629798, "validNegativeLandHeightPixelCount": 959, "hillshadeRange": [ 0.0, 0.9995848304984876 ], "landRgbMin": [ 189, 185, 164 ], "landRgbMax": [ 244, 240, 219 ] }, "reproduction": { "script": "scripts/prepare-mexico-relief-background.py", "scriptSha256": "447386c34c6d22de83603e36c447195151a52d832e8fb49b705c9f86632fee55", "command": "python scripts/prepare-mexico-relief-background.py --source --grid ", "dependencies": { "numpy": "2.5.3", "Pillow": "12.3.0", "shapely": "2.1.2" } }, "limitations": [ "2022 denotes the model edition, not a uniform observation year.", "60 arc-second source data and the 900x580 display raster give national visual context, not survey-grade or site-level elevations.", "Hillshade brightness depends on the disclosed illumination, display exaggeration and tone. It is not an elevation scale or a landform classification.", "The INEGI landform outlines retain their own source classification; this background does not replace or derive those categories.", "Valid negative elevations are retained. Mixed marine/terrestrial coastal source cells may influence coastal shading.", "Source/grid/image pixel counts and sampled height extrema are verification details, not national land area, state summaries or exact national extrema.", "The native-cell interpolation and finite differences use genuine source samples. No source gap is filled." ] }