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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.


Gildas manager 2018-02-18