Checksum Keyword Convention
Sample FITS File:
Sample Header Listing:
The CHECKSUM and DATASUM keywords that are embedded in the FITS header
are used to verify the integrity of the HDU. Verifying that the accumulated
32-bit 1's complement checksum of the HDU is equal to -0 provides
a fast and fairly reliable way to determine that the HDU has not been modified or
June 2007 by Rob Seaman (NOAO), William Pence (NASA/GSFC), and Arnold Rots (CXC/SAO)
Date and Place of First Usage:
1994, in the `Save the Bits' data archive at NOAO
1994 ADASS conference paper).
Extent of Usage:
The checksum keyword convention is used in data files from many different
observatories, including KPNO and the Chandra X-ray Center.
Public Comments about this convention:
The North American FITS committee reviewed this convention for possible
adoption as a FITS Standard. The comments may be seen in the archives of
the WGAS email list in
Last revised: Wednesday, 13-Jan-2021 16:56:06 EST
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