Upper plots: transfer functions T² for “AC” and “BD” for each spectral pixel and calibrator observation. The values for the individual spectral pixels are color-coded with respect to their corresponding wavelength (see legend in the upper left). The dashed lines are the corresponding 95% confidence intervals of the polynomial fits shown as solid lines. They gray data points are the computed T² values for the time of the science observation. Lower plots: calibrated visibilities for each spectral pixel.