Applying one RM to all the bursts detected during the observation of MJD 59243 and measuring the standard deviation of all the PA measurements from every time bin of every burst. Repeating this procedure for multiple RMs yields the black dots. The blue line is the fitted parabola. The vertical black line is the center of the fitted parabola. The red dashed vertical line is the RM measured after fitting using all the bursts. See Table 1 and Sect. 2.2.