Shown are all TSI time series (full line) with their uncertainty (green curve of the individual TSI plots, shown as shaded area), in (a) with the “org” and (b) the “corr” data sets. Note the difference in scale by a factor of 1.6 needed to include HF org. The determined offsets are used to shift the individual time series to a common level. Moreover, the SATIRE-S model provides a useful extension back to 1975 and supports the corrections of HF and ACRIM1 during solar cycle 21.