RESAMPLE SHAPE

    Four keywords are used to describe the frequency response of the synthe-
    sized channels:
    - TBOX  means  a  rectangular  function  in the delay domain, as for un-
            smoothed correlator channels (sin(pi.x)/(pi.x) in the  frequency
            domain)
    - TPAR  means  a parabolic function in the delay domain, as for smoothed
            correlator channels (smoothing function used at Plateau de Bure)
    - FBOX means a rectangular function in the frequency domain (as for fil-
            terbank channels)
    - FTRIANGLE means a triangular function in the frequency domain (as  for
            filterbank channels, Hanning smoothed)

    The  shape of the input channels is derived from the backend number read
    in the telescope name for IRAM-30m  spectra:  TBOX  for  autocorrelator,
    FBOX for other (filter) backends. Otherwise, rectangular filter channels
    are assumed.