{
  "review_date": "2026-10-25",
  "revision_reviewed": "R1.2-reference",
  "main_artifacts_edited": false,
  "overall": "CAD/source transformation consistency verified; current real-world dimensions and all heights/depths remain unverified.",
  "findings": [
    {
      "id": "M01",
      "priority": "correction before dimensioning",
      "finding": "Existing spherical cos-latitude correction retains directional ellipsoidal error.",
      "metrics": {
        "origin_lon_lat": [
          100.32143,
          5.3947
        ],
        "east_scale_r12_over_ellipsoid": 0.9999704135832315,
        "north_scale_r12_over_ellipsoid": 1.0066501419430331,
        "direction_norm": 0.9999999999999999,
        "edge_count": 327,
        "min_edge_difference_pct": -0.002930691440827804,
        "max_edge_difference_pct": 0.6646976903980084,
        "max_absolute_edge_difference_m": 2.7203938421411067,
        "site_area_r12_m2": 128231.91750929579,
        "site_area_ellipsoid_tangent_m2": 127388.20283437584,
        "site_area_difference_pct": 0.6623177469713637
      },
      "recommendation": "Use one ellipsoidal local transform consistently for drawing, CAD, register, imagery overlay and scale bar."
    },
    {
      "id": "M02",
      "priority": "measurement semantics",
      "finding": "SBR OSM polygons are tagged water outlines, not structural wall faces.",
      "recommendation": "Explicitly define measured edges and endpoints; do not force current geometry to approximate historical90x60m nominal twin footprint."
    },
    {
      "id": "M03",
      "priority": "uncertainty",
      "finding": "8.47m source positional metadata is not a dimension tolerance. Seven samples repeat one source record, not independent checkpoints.",
      "recommendation": "No CE90/RMSE/hardbound claim without record-specific documentation; separate global position from relative lengths."
    },
    {
      "id": "M04",
      "priority": "resolution",
      "finding": "~0.33m rendered pixel spacing resamples0.5m source resolution.",
      "metrics": {
        "pixel_size_web_mercator_m": [
          0.33156684269488323,
          0.33156684269488323
        ],
        "square_projected_pixels": true,
        "r12_cos_corrected_pixel_m": [
          0.3300982222704087,
          0.3300982222704087
        ],
        "ellipsoidal_local_nominal_pixel_m": [
          0.33010798898294935,
          0.32791752418894415
        ],
        "source_resolution_metadata_m": 0.5,
        "limit": "Rendered ~0.33m pixels are resampling of a source with metadata resolution0.5m; more display pixels do not improve source detail or positional accuracy."
      },
      "recommendation": "Do not claim0.33m source detail or dimensional accuracy."
    },
    {
      "id": "M05",
      "priority": "verification limit",
      "finding": "All46 source polylines match DXF exactly; units and local rotation consistent.",
      "metrics": {
        "INSUNITS": 6,
        "dxf_audit_error_count": 0,
        "polyline_count": 48,
        "expected_source_polyline_count": 46,
        "additional_historical_slot_count": 2,
        "source_polylines_match": true,
        "max_source_vertex_discrepancy_m": 0.0,
        "z_values": [
          0.0
        ]
      },
      "recommendation": "Report this as numerical export consistency only, not survey accuracy."
    },
    {
      "id": "M06",
      "priority": "vertical limit",
      "finding": "No physical Z, height, depth or vertical datum in available current geometry. All DXFZ=0 is a drawing plane.",
      "recommendation": "Leave current vertical dimensions unknown; qualify historical dimensions and distinguish structural height from water depth."
    }
  ],
  "bounds_recommendation": {
    "established_global_position_bound": null,
    "established_length_accuracy_bound": null,
    "reason": "Metadata lacks confidence metric and spatial error covariance; no independent surveyed checkpoints.",
    "illustrative_edge_pick_budget": "If endpoint selection radius r is explicitly assumed, worst-case distance sensitivity<=2r. One-to-two0.5m source pixels per endpoint implies1\u20132m sensitivity, excluding other unquantified errors. This is an illustration, not certified accuracy.",
    "recommended_presentation": "Rounded approximate values; raw computational figures separate; endpoint definitions, trace sensitivity and source/date retained."
  },
  "details_file": "findings.txt",
  "reproducible_check_script": "audit_r12.py",
  "numeric_results": "r12-mathematical-export-audit.json"
}