Shows the correction computed by self calibration. By default, the difference between the last two iterations is displayed: phase should be around 0, and amplitude around 1 if the solution is converged.
If Last and First are present, it shows the difference between these two specified iteration. If Last only is present, it shows the total correction between the original data and that iteration.
The displayed ranges are controlled by SELF_ARANGE[2] (limits of Amplitude gain), SELF_PRANGE[2] (limits of Phase correction) and SELF_TRANGE[2] (limits for time axis).