{
  "schema": "kendraya-engine-validation-summary-1",
  "title": "Kendraya Engine position audit against NASA/JPL Horizons",
  "publisher": "Kendraya",
  "page": "https://kendraya.com/how-it-works#accuracy",
  "auditedAt": "2026-10-04T00:15:49.666Z",
  "internalReportSha256": "4b0a3d2bc4a210af5b99f3b508c310cce553ce4762b98e51a2d92434b6b76b59",
  "engine": {
    "name": "Kendraya Engine",
    "version": "kendraya-jpl-2",
    "datasetVersion": "de440s-iers-2026-09-30",
    "ephemeris": "NASA/JPL DE440s",
    "ephemerisSource": "https://naif.jpl.nasa.gov/pub/naif/generic_kernels/spk/planets/de440s.bsp",
    "ephemerisSha256": "c1c7feeab882263fc493a9d5a5b2ddd71b54826cdf65d8d17a76126b260a49f2",
    "earthRotationDataSha256": "051fdbb46896f482f4e77484845ebbccb284e3f3a6d274930ed368240e9d798c",
    "kernelCoverageTdb": [
      "1849-12-26T00:00:00",
      "2150-01-22T00:00:00"
    ],
    "supportedYears": [
      1900,
      2100
    ],
    "quantity": "Apparent geocentric ecliptic longitude and latitude of date (IAU 1976 precession, IAU 1980 nutation)",
    "runtimeNetworkRequired": false
  },
  "reference": {
    "service": "NASA/JPL Horizons System",
    "documentation": "https://ssd.jpl.nasa.gov/horizons/manual.html",
    "capturedAt": "2026-09-30T23:05:33.899Z",
    "ephemerisReportedByService": "DE441 and body-specific JPL satellite solutions, as recorded in the archived Horizons responses",
    "observer": "Geocentric (500@399)",
    "timeScale": "TT",
    "quantity": "Horizons quantity 31: observer ecliptic longitude and latitude of date (IAU76/80), apparent",
    "targets": "Body centres for every body"
  },
  "sampling": {
    "epochs": 256,
    "bodies": 10,
    "longitudeLatitudePairs": 2560,
    "firstEpochTT": "1900-01-01",
    "lastEpochTT": "2100-12-31",
    "passThresholdArcsecondsPerAxis": 5,
    "failures": 0
  },
  "results": [
    {
      "body": "Sun",
      "engineTarget": {
        "naifId": 10,
        "centre": "body centre"
      },
      "referenceTarget": 10,
      "samples": 256,
      "maxLongitudeArcseconds": 0.12032,
      "maxLatitudeArcseconds": 0.000209
    },
    {
      "body": "Moon",
      "engineTarget": {
        "naifId": 301,
        "centre": "body centre"
      },
      "referenceTarget": 301,
      "samples": 256,
      "maxLongitudeArcseconds": 0.119157,
      "maxLatitudeArcseconds": 0.000603
    },
    {
      "body": "Mercury",
      "engineTarget": {
        "naifId": 199,
        "centre": "body centre"
      },
      "referenceTarget": 199,
      "samples": 256,
      "maxLongitudeArcseconds": 0.120258,
      "maxLatitudeArcseconds": 0.000188
    },
    {
      "body": "Venus",
      "engineTarget": {
        "naifId": 299,
        "centre": "body centre"
      },
      "referenceTarget": 299,
      "samples": 256,
      "maxLongitudeArcseconds": 0.218293,
      "maxLatitudeArcseconds": 0.756534
    },
    {
      "body": "Mars",
      "engineTarget": {
        "naifId": 4,
        "centre": "system barycentre"
      },
      "referenceTarget": 499,
      "samples": 256,
      "maxLongitudeArcseconds": 0.120331,
      "maxLatitudeArcseconds": 0.000196
    },
    {
      "body": "Jupiter",
      "engineTarget": {
        "naifId": 5,
        "centre": "system barycentre"
      },
      "referenceTarget": 599,
      "samples": 256,
      "maxLongitudeArcseconds": 0.16822,
      "maxLatitudeArcseconds": 0.003471
    },
    {
      "body": "Saturn",
      "engineTarget": {
        "naifId": 6,
        "centre": "system barycentre"
      },
      "referenceTarget": 699,
      "samples": 256,
      "maxLongitudeArcseconds": 0.162431,
      "maxLatitudeArcseconds": 0.023161
    },
    {
      "body": "Uranus",
      "engineTarget": {
        "naifId": 7,
        "centre": "system barycentre"
      },
      "referenceTarget": 799,
      "samples": 256,
      "maxLongitudeArcseconds": 0.283995,
      "maxLatitudeArcseconds": 0.009581
    },
    {
      "body": "Neptune",
      "engineTarget": {
        "naifId": 8,
        "centre": "system barycentre"
      },
      "referenceTarget": 899,
      "samples": 256,
      "maxLongitudeArcseconds": 0.216988,
      "maxLatitudeArcseconds": 0.005583
    },
    {
      "body": "Pluto",
      "engineTarget": {
        "naifId": 9,
        "centre": "system barycentre"
      },
      "referenceTarget": 999,
      "samples": 256,
      "maxLongitudeArcseconds": 0.1915,
      "maxLatitudeArcseconds": 0.093481
    }
  ],
  "limitations": [
    "This is sampled agreement at 256 fixed TT instants, not proof of accuracy at every instant.",
    "The reference and the bundled data come from the same JPL ephemeris family. Differences include ephemeris and target-point choices as well as Kendraya's calculation. This checks computed output; it is not a bound on accuracy against real observations.",
    "Comparisons use Terrestrial Time directly. They do not test the conversion of a recorded birth clock time to UTC and UT1.",
    "Mars through Pluto are computed at their system barycentres, while Horizons reports body centres.",
    "Ascendants, houses, nodes, ayanamsa values, dasha dates and every traditional interpretation are outside this comparison.",
    "Future dates use modelled Earth rotation and assume no unannounced leap seconds."
  ],
  "sources": [
    "https://ssd.jpl.nasa.gov/doc/de440_de441.html",
    "https://doi.org/10.3847/1538-3881/abd414",
    "https://naif.jpl.nasa.gov/pub/naif/generic_kernels/spk/planets/",
    "https://ssd.jpl.nasa.gov/horizons/manual.html",
    "https://naif.jpl.nasa.gov/naif/rules.html",
    "https://datacenter.iers.org/data/latestVersion/EOP_20u24_C04_one_file_1962-now.txt",
    "https://datacenter.iers.org/data/9/finals2000A.all",
    "https://maia.usno.navy.mil/ser7/historic_deltat.data",
    "https://hpiers.obspm.fr/iers/bul/bulc/Leap_Second.dat",
    "https://eclipse.gsfc.nasa.gov/SEhelp/deltatpoly2004.html",
    "https://github.com/liberfa/erfa"
  ],
  "notices": "https://kendraya.com/calculation-notices.txt",
  "endorsement": "NASA, JPL, IERS and the ERFA/SOFA authors do not endorse Kendraya."
}