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LINE

    [PDBI\]LINE Name Frequency Band [Lock [Center [Harm]]]

    Define  and  plot the receiver frequency coverage of the Plateau de Bure
    Interferometer (with the receivers installed in winter 2006/2007).   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 rest frequency in GHz
        Band      should be USB or LSB
        Lock      is LOW or HIGH [optional, default LOW]
        Center    is the IF1 frequency in MHz [optional, default 6500]
        Harm      is the harmonic number [optional]

    o The receiver band to be used (1 to 4) will be determined by the  soft-
    ware.

    o The center frequency is expressed in the first IF (4-8 GHz = 4000-8000
    MHz). WARNING: it is highly not recommended to center the line frequency
    at  6 GHz. This is because the correlator analyses quarters of the 4 GHz
    bandwidths, and 6 GHz is very precisely at the limit  between  two  such
    adjacents quarters.

    o  The plot displays the four "quarters" Q1...Q4 that can be selected as
    input for the correlator (see NARROW_INPUT command):
      Q1 = 4.2-5.2 GHz, Q2 = 5.0-6.0 GHz
      Q3 = 6.0-7.0 GHz, Q4 = 6.8-7.8 GHz

    o Commands NARROW and SPECTRAL are available to setup the  IF  processor
    and  the  spectral  units  of the narrow-band correlator (see the corre-
    sponding help). A typical ASTRO session would look like:

    line toto 100 usb           ! choice of rx tuning
    narrow q1 q3                ! choice of the correlator windows
    spectral 1  20 320 /nar 1   ! correlator unit 1
    spectral 2 320 200 /nar 2   ! correlator unit 2
    spectral 2 320 210 /nar 2   ! new def. of unit 2 --> plot is updated

    o Command PLOT can be used to plot the full receiver coverage,  that  of
    the NARROW band correlator, or that or the WIDEX correlator.

    o  LINE  can  also be used to produce plots of the frequency coverage of
    the old receivers (replaced in 2006/2007). The command SET PDBI year al-
    lows one to select the instrument as of the selected year:
    - 1995: 3 and 1.3 mm receivers, 500 MHz bandwidth
    - 2000: 3 and 1.3 mm receivers, 580 MHz bandwidth
    - 2006: new generation receivers (4 GHz bandwidth, 2 polar.) [default]
    For  the  OLD  receivers (years 1995 & 2000), the commands NARROW, SPEC-
    TRAL, PLOT are not active. Please enter HELP LINE OLD for a  description
    of the behaviour of the LINE command in that case.


Subsections

Gildas manager 2011-09-07