{
  "status": "approximate_not_survey_registered",
  "sourceScene": "ulg-map",
  "sourceId": "rns-9769143",
  "candidateCRS": "EPSG:32733 \u2014 WGS84 / UTM zone33S, assumed; issuer does not specify datum",
  "sourceFrame": "476\u00d7416 source-image pixels, unchanged in original scene",
  "transform": {
    "easting": "493000 + (x - 31) * 500 / 126",
    "northing": "7546000 + (67 - y) * 500 / 126.5",
    "empiricalShiftMetres": [
      0,
      0
    ]
  },
  "controls": {
    "eastings": [
      [
        31,
        493000
      ],
      [
        157,
        493500
      ],
      [
        283,
        494000
      ],
      [
        409,
        494500
      ]
    ],
    "northings": [
      [
        67,
        7546000
      ],
      [
        194,
        7545500
      ],
      [
        320,
        7545000
      ]
    ],
    "kind": "printed grid ticks, internal controls only"
  },
  "residuals": {
    "eastHoldoutMetres": 0,
    "northMiddleTickMetres": 1.9762845849618316,
    "interpretation": "Internal map-grid closure; not independent positional accuracy."
  },
  "geographicCrosschecks": [
    {
      "kind": "regional plausibility",
      "finding": "Grid centre493800E/7545600N transforms to14.939852E,22.194890S, in the disclosed Erongo setting and near the8995 environmental map centre; this is not boundary or title verification."
    },
    {
      "kind": "qualitative independent imagery comparison",
      "finding": "Unshifted 2026-09-30 Sentinel crop displays the same broad northeast-oriented ridge/drainage fabric and southern curved drainage pattern visible in the issuer basemap. No surveyed control or automated match accuracy is claimed.",
      "asset": "derived/geographic-v4/ulg-grid-crosscheck.png"
    }
  ],
  "limitations": [
    "Issuer CRS/datum remains unconfirmed; alternative datum/systematic displacement is unquantified.",
    "Source digitisation uncertainty remains feature-specific; no surveying precision is inferred.",
    "Do not use the historical Bessel/Albers grant frame as if it were the issuer grid.",
    "The overlay is display-only and optional, not a current licence boundary or geological model.",
    "Surface symbols drape on the DSM; height does not represent measured collarRL or trench excavation depth."
  ],
  "independentSurveyControls": 0,
  "cutoff": "2026-09-30"
}