Cylindrical Stokes-I power spectra after DD calibration (left) processed by the standard LOFAR-EoR pipeline with SAGECAL and GPR foreground removal (right) of a single observation night on the NCP. The dashed lines indicate the 5° (primary beam), 20°, and 90° (instrumental horizon) delay lines from the phase centre (from bottom to top). Some bad quality data are flagged on the right.