The following example changes the RA phase centre by 10 seconds of time and also corrects a delay error of -3 ns on antenna 2 (by adding a phase gradient across the band). uvedit has the option to turn off the recomputation of u and v which might otherwise be done (options=nouv). This can be useful for say, entering a delay change (which does not need u and v to be recomputed) because Miriad does not compute u and v as accurately as the on-line ephemeris routines.
|Input visibility dataset
|Specify source; unset means all
|No change to antenna coordinates
|Move RA phase centre
|No change to DEC
|No clock offset
|Delay error on antenna 2
|Output visibility dataset
|Do the works
The task uvredo also `edits' a visibility dataset. Unlike uvedit, however, it only modifies ancillary data in the dataset that are derivate from other information. For example, it can recompute the sky feed angle (``chi'') and velocity information.