Basic Information on gpboot

Task: gpboot
Purpose: Correct the gains table of a visibility data-set.
Categories: calibration

        GpBoot is a MIRIAD program which corrects a visibility data-set's
        gain table.
 
        GpBoot works by comparing the amplitudes in the gain table of one
        data-set with those of another. The gains are assumed to differ
        by a constant factor. It is assumed that the
        instrumental gain and atmospheric attenuation of the two datasets
        were the same, and so the difference in gain is due to an
        arbitrary or incorrect flux being specified when initially
        determining the gains.

Key: vis
        The input visibility file, containing the gain file to correct.
        The gains are assumed to be out by a constant factor.

Key: cal
        This is a visibility data-set, which is assumed to contain a
        gain table which scales the data to absolute flux units.

Key: select
        Normal uv-selection parameter. This selects the gains in the
        ``vis'' that are compared against the ``cal'' gains (note that
        all the ``cal'' gains are involved in the comparison). Currently
        ONLY time and antenna selection are permitted. You will use
        this parameter to select which data the instrumental/atmospheric
        amplitude gains for ``vis'' are comparable to the observation in
        ``cal''.