... CORWTFN specifies the weighting function to be used on the VLBA correlator. The weighting function is applied by weighting the data points before they are sent to the FFT. Valid options are: . ... The is the option that most users will want. ... HANNING . With this option, a Hanning weighting is applied in before the FFT. ... With this option, an approximation of a ``root Hanning'' weighting is applied to get close to the expected Hanning response in the power domain after correlation. ...