{
  "source": "NASA/TP-2000-210387",
  "source_record": "https://ntrs.nasa.gov/citations/20000095934",
  "source_pdf": "https://ntrs.nasa.gov/api/citations/20000095934/downloads/20000095934.pdf",
  "source_sha256": "12867527b3417f5f99a39c2bae26b663a2d297157c565ccf3f6d4a1402f41bdf",
  "figure_number": 1,
  "printed_page": 3,
  "pdf_page": 9,
  "source_crop": {
    "file": "nasa2000-figure1-source-crop.png",
    "sha256": "9be6b06b4ed33315be7c685ccd569e148275655a4059224d2a17bcf2b54535cc",
    "dimensions_pixels": [1425, 1374],
    "crop_rectangle_pdf_points": [90, 267, 565, 725],
    "render_scale": 3,
    "recreation_script": "nasa2000-figure1-source-crop.py"
  },
  "styled_redraw": "nasa2000-figure1.svg",
  "redraw_status": "Qualitative restyling, not pixel-faithful tracing or numerical data extraction.",
  "elements_preserved": [
    "Two-panel layout: generic MHD-bypass engine and qualitative enthalpy-entropy path",
    "Flow direction and upstream-generator/downstream-accelerator topology",
    "Labels for stations a, 1, 2, 3, 4, 5, 6 and 10",
    "Pre-ionizer, diffuser, MHD generator, combustor, MHD accelerator, nozzle and power-conditioning labels",
    "Qualitative pressure-guide labels and temperature-limit line"
  ],
  "elements_redrawn_approximately": [
    "Component positions and engine contours",
    "The curves and trajectories in the enthalpy-entropy panel",
    "Spacing, typography and colour palette"
  ],
  "uncertainty_and_limits": [
    "The lower panel has no numerical axes; no coordinates or performance data are digitized.",
    "The exact terminal point of the lower-left return arrow is ambiguous in the source scan.",
    "The drawing illustrates a generic analyzed concept, not a built or flight-validated engine.",
    "The source crop is supplied to let readers compare the NASA page directly with the styled redraw."
  ]
}