MODIFY BUG

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MODIFY BUG

            CLIC\MODIFY BUG number

        This command is reserved for the correction of nasty bugs  in  the  data
        acquisition.  The number is used for identification.

        Current accepted values:

          1  Affecting  data  taken between 11-nov-1995 and 09-jan-1996.  Bug in
            RDI found by S.Guilloteau. The continuum data was erroneously  cali-
            brated  in  the  real-time aquisition. As result, the continuum data
            did not agree with the average of the spectral data.   For  instance
            plotting  data  with  "set  sub C02 L02" as a function of time gives
            different results for C02 and L02. The result would affect line  in-
            tensities  if,  as is usually the case, the amplitude calibration is
            done with the continuum subbands.

            Correction: the current index should contain both  atmosphere  cali-
            brations and correlation data; the data file should be open for both
            input and output.  This command should not affect data taken  before
            11-nov-1995 and after 09-jan-1996; be careful for the last day since
            the hour is not checked, and RDI was corrected at 3pm.

          2 Affecting data taken between 26-jan-2015  and  05-mar-2015.  Bug  in
            correl after change of commons to 7 antennas. Consequence is a phase
            offset between narrow band correlator units and widex units  depend-
            ing on elevation and baseline.

            MODIFY  BUG  2  will correct the bug. Warning: this correction is an
            offset to the phases, so it should be applied only once. If the cor-
            rection  is  done  on data file (IPB), there is a check that this is
            the case, but header files (HPB) are not protected against  correct-
            ing twice.

          3  Affects  data reduced with a CLIC version compiled from 15-jun-2023
            to 19-oct-2023, if HR spw are present and any MODIFY (ANTENNA, BASE,
            DELAY  ...)  was done in lowres mode. In that case, CLIC stored data
            modifiers only for the low-resolution spectral windows.

            MODIFY BUG 3 will check the data modifier from both LR and  HR,  and
            if they do not match will apply the complement of LR to HR.