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List of keywords for image data

May 2005

This is a list of keywords that you might consider for image data. Some of them are probably inappropriate in the case of composite images. However, we encourage you to browse through them and think about which ones might apply to your particular HLSP.

KeywordDescription
  
TARGNAMEtarget name (according to raw data or catalog)
IMTYPE image type (e.g. cutout, coaddition, resampled)
TELESCOP observatory (e.g. HST, IUE, ISO, ESO-VLT1)
INSTRUME instrument (e.g. WFPC2, ACS, ISOCAM, TIMMI2)
INSTMODE full description of instrument setting (e.g. ACS WFC1 F475W)
APERTURE aperture of the instrument
WAVECENT central wavelength
(DETECTOR) detector of the instrument
(FILTER[n]) filters
(POSANGLE) position angle
  
OBSDATE date of observation
EXPSTART start time of observation
EXPEND end time of observation
EXPTIME effective exposure time (seconds)
  
NAXIS number of data axis
BITPIX number of bits that represent a data value
NAXIS[n] number of points on axis [n]
AXIS[n] name of axis [n]
AUNIT[n] unit of axis [n]
CRPIX[n] pixel at axis origin
CRVAL[n] value at axis origin
CDELT[n] increment
CTYPE[n] description of axis (array)
  
MINFLUX minimum flux
MINFUNIT minimum flux unit
MAXFLUX maximum flux
MAXFUNIT maximum flux unit
RESOLUTIO spatial resolution
... data quality
... limiting magnitude

Examples for image headers

There are links to sample FITS headers for some HLSP. Please note that these headers were created prior to the current guidelines and may not fully meet the current standards.