Median-quantile-values for the calculation error for (a) the all-rigid box, calculated with the ESIE method only, and (b) the box with an impedance patch, calculated with the ESIE+SS method. In both diagrams, the quantile values are given for 18 frequencies, including those not shown in Figures 9 and 11. The median and quantile values were based on the 181 receiver angle values shown in Figures 9 and 11. In (c) results for all frequencies and all 181 receiver positions were pooled into one dataset. Note the different scale in (c).