FitsKeywords

WSClean adds the following non-standard keywords to its output FITS files:

General

WSCVERSI -- Version string for WSClean, e.g. "2.5.1"  (since WSClean 2.5).
WSCVDATE -- Version date of WSClean, e.g. "2017-05-08"  (since WSClean 2.5).
WSCNWLAY -- nwlayers
WSCDATAC -- data column
WSCWEIGH -- weighting (textual description, e.g. uniform or Briggs'(0.5))
WSCGKRNL -- gridding (antialiasing) kernel size
WSCCHANS / WSCCHANE -- channel range (only when specified)
WSCTIMES / WSCTIMEE -- time range (only when specified)
WSCFIELD -- imaged field number in MS
WSCNVIS  -- gridded visibility count
WSCENVIS -- effective nr of visibilities (only for natural weighting)
WSCVWSUM -- sum of visibility weight (since WSClean 2.3)
WSCIMGWG -- Weight to be used when averaging images together
WSCNORMF -- Normalization factor that was applied to the image. The factor is
            useful to undo the normalization for e.g. conversion to Kelvins.
            WSCNORMF is available since WSClean 2.
WSCTHRES -- Manually applied threshold

Cleaning

WSCNITER -- max number of iterations specified
WSCGAIN -- clean gain (minor iteration gain)
WSCMGAIN -- major cleaning gain
WSCNEGCM -- whether negative components were allowed to clean
WSCNEGST -- whether stopping on first negative component during clean
WSCMAJOR -- number of major iterations actually used before reaching stopping criteria
WSCMINOR -- number of minor iterations actually used before reaching stopping criteria

The actually used number of major/minor iterations are stored in WSCMAJOR and WSCMINOR, whereas WSCMGAIN and WSCNITER describe the input parameters.

No longer used

WSCSMPSF -- whether the PSF is made smaller prior to cleaning