Fig. 6

The improved assimilation results using an additional prior spatial correlation in the case of identical true and imposed magnetic fields. Again, the upper plots show the absolute deviation of the final scale factor \({\mathbf{k}}_{f}\) from the true value of 1 on the left and the associated uncertainty (posterior standard deviation) of the final scale factor \(\sigma _{{\mathbf{k}}_{f}}\) on the right. The bottom plots present the corresponding temporal average of the radial rescaled OIMF \(\overline{{\mathbf{B}}}_{r}^{\text{rescaled}}\) on the left. And its deviation from the temporal averaged true radial OIMF \(\overline{{\mathbf{B}}}_{r}^{\text{true}}\) are shown on the right