Comparisons of images derived from independent Zeeman Doppler imaging codes

We compare surface brightness and magnetic field surface maps for the K0 dw arf AB Doradus, obtained using two independently developed Zeeman Doppler i maging codes. We find that even the fine structure in the two sets of image s shows excellent agreement. Magnetic field maps appear to be less sensitiv e to line-modelling effects than brightness maps. We argue that these resul ts point to the consistency and reliability of Doppler imaging techniques e ven when using poorly sampled data sets, provided that the spectra used are of sufficiently high signal-to-noise ratio.