Comparisons of the two position-finding methods on AR 11310 (left) and AR 11640 (right). The blue, orange, and green symbols mark the position of the leading and trailing polarity and the center of the AR, respectively. The crosses and diamonds refer to coordinates derived with the method described in Sect. 3.2 and the method described by Schunker et al. (2019), respectively. The axis labels are relative coordinates provided by the HEAR survey. The background images show the radial field B_z. The gray scale saturates at ±500 Gauss.