{
  "title": "Approximate digitization of NASA Figure 19: X-43A Mach-7 vertical-tail thermocouple T093",
  "type": "source-figure redraw; digitized estimates, not raw telemetry",
  "source": {
    "citation": "Amundsen, R. M., Leonard, C. P. and Bruce, W. E. III (2004), Hyper-X Hot Structures Comparison of Thermal Analysis and Flight Data, NASA NTRS 20040111308, Figure 19, physical PDF page 21; textual crossing discussion on physical PDF page 20.",
    "record_url": "https://ntrs.nasa.gov/citations/20040111308",
    "pdf_url": "https://ntrs.nasa.gov/api/citations/20040111308/downloads/20040111308.pdf",
    "pdf_sha256": "92F555C8C2045D6CA0129D7661E71F018F8961F30DCE80210A73245F117DD8D0",
    "figure_raster_sha256": "1C7BF75E6CF70C8CED3D62BD8C6AD30E47DDC263144E883C0DE76B5A13927BAB"
  },
  "digitization": {
    "method": "Approximate color-centerline readings from the published plot raster at 10-second intervals generally, refined to 5-second intervals from 60 to 90 seconds around the crossing; calibrated to the printed axes. Straight connectors are visual guides only.",
    "plot_bounds_in_1800x2330_source_raster_px": {
      "left": 473,
      "right": 1392,
      "top": 224,
      "bottom": 759
    },
    "x_axis_s": [
      0,
      140
    ],
    "y_axis_F": [
      -50,
      1950
    ],
    "nominal_typical_reading_uncertainty_F": 35,
    "overlap_or_crossing_reading_uncertainty_F": 60,
    "source_supplied_event": "NASA text on physical PDF page20 reports T093 and T094 above the +35% heat-flux case at about83s. The project digitized points interpolate to81.67s, displayed as near82s. The project assigns a heuristic +/-2s reading allowance, not a calibrated uncertainty or NASA error bar.",
    "initial_flight_point_note": "The plotted 0-second flight value is approximate. The authors say most thermocouples were about -40 F at drop; this is not a separately tabulated T093 reading.",
    "flight_trace_limit_note": "The source T093 flight trace ends near 90 seconds. Blank CSV values afterward mean no curve is plotted; no flight temperature is extrapolated.",
    "uncertainty_scope": "Project-chosen visual-reading allowances only, not NASA-supplied measurement uncertainties, statistical confidence intervals, calibrated digitization errors or validated coverage bounds. No retained repeated-reader or pixel-error propagation study establishes the quoted allowances.",
    "crossing_time_digitization_uncertainty_s": 2,
    "reading_allowance_basis": {
      "status": "heuristic_not_calibrated",
      "typical_temperature_F": 35,
      "overlapping_curves_temperature_F": 60,
      "crossing_time_s": 2,
      "provenance": "Values assigned in the project transcription. They are not derived by the plotting script or supplied as error bars in the source.",
      "crossing_interpolation": "Linear interpolation of the two recorded curve differences at80s and83s gives81.67s; that arithmetic does not establish the2s allowance."
    }
  },
  "interpretation_limits": [
    "NASA describes this as the 27 March 2004 Mach-7 X-43A powered flight; comparison covers the measured/test interval, not the later Pacific descent.",
    "Figure 19 plots thermocouple T093 on a forward thin-skin area of the vertical tail. The text also discusses T094, but Figure 19's plotted record is T093.",
    "The +35% case is a design heat-flux factor, not a 35% temperature error bar or a statistical confidence interval.",
    "The NASA paper says most predictions were conservative, but T093 and T094 exceeded the +35% case at about 83 seconds. It proposes an unmodeled local flow pattern as a hypothesis; its attempted artificial shock augmentation did not reproduce the flight behavior. Cause remains unresolved.",
    "The source gives no tabulated curve values. The CSV is an approximate transcription from pixels, not a recovered telemetry record or new measurement.",
    "The separate Mach-10 leading-edge arc-jet campaign in NASA NTRS 20050240163 tested 13 material systems for simulated 130-second heating. It does not publish complete candidate-by-candidate numerical response data; this Site does not rank coatings from it."
  ],
  "dataset": "x43a-t093-figure19-digitized.csv",
  "reproduction_script": "reproduce_t093_figure19.py",
  "figure": "x43a-t093-figure19-digitized.svg",
  "separate_material_source": {
    "citation": "Ohlhorst et al. (2005), Development of X-43A Mach 10 Leading Edges, NASA NTRS 20050240163.",
    "record_url": "https://ntrs.nasa.gov/citations/20050240163",
    "pdf_url": "https://ntrs.nasa.gov/api/citations/20050240163/downloads/20050240163.pdf",
    "pdf_sha256": "7F750ACF70EE17EACFBD4988CC66E2AFAAAC9F6DAD2336E97FA8AE9C3F55D6E6"
  },
  "figure_png": "x43a-t093-figure19-digitized.png",
  "figure_mobile": "x43a-t093-figure19-digitized-mobile.svg"
}