{
  "schema": "midget-filter-rim-axis-survey-v1",
  "units": "mm",
  "method": null,
  "basis": null,
  "filter_marking_observation": null,
  "photo_refs": [],
  "frame": {
    "name": null,
    "origin_datum": null,
    "x_positive": null,
    "y_positive": null,
    "z_positive": null,
    "configuration": null,
    "right_handed_orthonormal": null
  },
  "survey": {
    "same_circular_rim_section_confirmed": null,
    "rim_section_datum_note": null,
    "rim_points": [
      {"name": "P1", "xyz_mm": [null, null, null], "datum_note": null},
      {"name": "P2", "xyz_mm": [null, null, null], "datum_note": null},
      {"name": "P3", "xyz_mm": [null, null, null], "datum_note": null},
      {"name": "P4 independent check", "xyz_mm": [null, null, null], "datum_note": null}
    ],
    "closed_end_point_on_extreme_plane_normal_to_axis_confirmed": null,
    "closed_end_plane_point_xyz_mm": [null, null, null],
    "closed_end_plane_datum_note": null
  },
  "independent_dimensions_mm": {
    "rim_section_outside_diameter": null,
    "rim_plane_to_closed_end_plane": null,
    "measurement_point_and_method_note": null
  },
  "limits": "Blank direct spatial survey. Capture a reproducible circular rim section and a confirmed closed-end extreme-plane point in one unchanged physical frame during planned access. This rim plane is not a gasket sealing plane or the overall-height datum. Outputs are reference wires only, not material, engine placement or a removal path. Do not fill missing coordinates from photographs or the public CAD."
}