Left: best-fit calibration parameters as a function of channel index, as determined from the analysis of observations of a selection of pulsars (conducted between MJDs 59368 and 59373; see Table 1 for details) and of observations of the noise diode conducted prior to the pulsar observations. During the pulsar observations, the feed horn was made to rotate by 180° between the beginning and the end of the observation. The absolute gain G is expressed in units of the square root of the noise diode flux density in the considered frequency channel, $c_0=\sqrt{C_0}$. The two top panels show the feed ellipticities, ε₀ and ε₁, and the feed orientation parameter θ₁. Right: best-fit parameters from the analysis of the same observations, after correction of the expression for the parallatic angle to be used in the case of NRT observations.