LINE

        [ASTRO\]LINE Name Frequency Band [Lock [Center [Harm]]]  [/MOLECULES
    File] [/SPECTRAL Unit Bandwidth IF_2] /WIDTH width
        [ASTRO\]LINE/SPECTRAL Unit Bandwidth IF_2

    Plot rest frequency coverage of Plateau  de  Bure  Interferometer.   The
    command syntax is identical to that of the corresponding command in OBS.
        Name is a line name to label the plot
        Frequency is the center frequency in GHz
        Band should be USB or LSB
        Lock (optional) is LOW or HIGH
        Center (optional), the center IF2 frequency in MHz, default 350.
        Harm (optional), the harmonic number.
    The option /MOLECULES enables to plot the rest  frequencies  of  several
    transitions, found in file File. This is a text file with entries:
        Freq    'chain'
        where Freq is the rest frequency in GHz and 'chain' the line name to
        be plotted by GreG, between single quotes. Example:
        88.632  'HCN'
        89.081  'HCO\u+'
    The option /WIDTH width is used to introduce a finite  width  (in  km/s)
    for the molecular lines displayed.

    The option /SPECTRAL is used to overlay the desired spectral  correlator
    configuration.
        Unit is the correlator unit number (1 to 6)
        Bandwidth is the bandwidth in MHz (10, 20, 40, 80 or 160)
        IF_2 is the center frequency (in MHz) of the unit in the  second  IF
        (in the range 110 to 590 MHz).

    With only the /SPECTRAL option, the corresponding unit overlay  will  be
    drawn on an existing LINE plot.

    Because only one synthesizer is used to generate the 1st  and  2nd  LOs,
    the IF frequency is slightly variable (between 1.500 and 1.550 GHz), and
    the Doppler tracking is correct only for  the  specified  band  (USB  or
    LSB).   The last specified source is used to get the Doppler shift.  The
    image frequency doppler shift is wrong by at most 2.Ers/Harm, where  Ers
    is  the Earth rotation speed, or about 0.9 km/s, roughly 0.04 km/s at 86
    GHz.