RHT backprojection depicting depolarisation canals (red lines) overplotted on the maximum polarised intensity image of the whole LoTSS mosaic. The blue bars on top of the two represent the sample of starlight polarisation measurements. They are coloured according to their distance, as indicated by the lower colour bar. The orientation of the lines represents the orientation of the starlight polarisation angle in the same projection as the LoTSS data.