Keywords: class-spectral-axis-v12

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## Stopping the periodic dilatation

At IRAM-30m, G. Paubert proposes to stop the periodic dilatation in the rest frequency by adapting the channel spacing of the spectrometer frequency comb in real time. This in combination with LO tuning will stop all temporal variations of the frequency axis, removing the need for resampling when averaging spectra observed at different time of year.

This proposition is equal to a change of reference frame for the channel spacing. Due to hardware limitation, this change of frame can only be done from the observatory to the barycentric frame. This implies that adaptation of the frequency channel spacing when going from the barycentric frame to the source rest frame will still be needed.