{
  "status": "shipping",
  "supersedes": [],
  "supersededBy": [],
  "firstSeen": null,
  "lastSeen": null,
  "updated": "2026-10-18",
  "advantages": [],
  "limitations": [],
  "slug": "fits",
  "term": "Flexible Image Transport System (FITS)",
  "aliases": [
    "FITS"
  ],
  "definition": "FITS is a scientific data format that stores images and other data in header/data units with metadata describing their representation.",
  "note": "Image interpretation: BSCALE and BZERO map stored values to physical values; preserving image payload bytes alone does not preserve that interpretation if the header changes. Astropy normally applies this scaling when image data is accessed. [scaling]\n\nIntegrity: the registered CHECKSUM and DATASUM convention checks an HDU and its data records respectively. It is optional, so a readable FITS file need not contain these checks. Verify the expected HDU inventory separately from the checks of units that remain. [convention] [astropy-checks] [hesela-fits]",
  "related": [
    "fits-checksum",
    "checksum",
    "file-storage",
    "hdf5",
    "parquet"
  ],
  "citations": [
    {
      "id": "convention",
      "title": "NASA FITS registry: Checksum Keyword Convention",
      "url": "https://fits.gsfc.nasa.gov/registry/checksum.html",
      "accessed": "2026-10-18"
    },
    {
      "id": "astropy-checks",
      "title": "Astropy: verification using the FITS checksum keyword convention",
      "url": "https://docs.astropy.org/en/stable/io/fits/usage/verification.html#verification-using-the-fits-checksum-keyword-convention",
      "accessed": "2026-10-18"
    },
    {
      "id": "scaling",
      "title": "Astropy: FITS image scaling with BSCALE and BZERO",
      "url": "https://docs.astropy.org/en/stable/io/fits/usage/image.html#scaled-data",
      "accessed": "2026-10-18"
    },
    {
      "id": "hesela-fits",
      "title": "FITS archive checks: reordered pixels can preserve both checksums",
      "url": "https://hesela.com/analyses/fits-checksums-pixel-order-and-coverage/",
      "accessed": "2026-10-18"
    }
  ]
}