Basic Information on uvspec

Task: uvspec
Purpose: Plot averaged spectra of a visibility dataset.
Categories: uv analysis

        UVSPEC plots averaged spectra of a visibility dataset. Averaging can
        be in both time and frequency

Key: vis
        The name of the input uv data sets. Several can be given (wild
        cards are supported). No default.

Key: select
        The normal uv selection commands. The default is plot everything.

Key: line
        The normal uv linetype in the form:
          line,nchan,start,width,step
        The default is all channels (or all wide channels if there are no
        spectral channels).

Key: stokes
        The Stokes/polarization types to be plotted. The default is to
        plot those polarizations present in the input files. Note that
        stokes=q,u is adopted when the X axis is RM or the Y axis is polang,
        regardless of Stokes input given.

Key: interval
        Time averaging interval, in minutes. The default is 0 (i.e. no
        averaging).

Key: hann
        Hanning smoothing width (an odd integer).  Smoothing is
        applied after averaging. Default is 1 (no Hanning smoothing).

Key: offset
        An offset (in arcsec) to shift the data. Positive values result in
        the data center being shifted to the North and East. Two values
        should be given, being the shift in the RA and DEC directions.
        The default is 0,0 (i.e. no shift).

Key: options
        This gives extra processing options. Several options can be given,
        each separated by commas. They may be abbreviated to the minimum
        needed to avoid ambiguity. Possible options are:
           'nocal'       Do not apply the gains file. By default, UVSPEC
                         applies the gains file in copying the data.
           'nopass'      Do not apply bandpass corrections. By default,
                         UVSPEC corrects for the bandpass shape if the
                         required information is available.
           'nopol'       Do not apply polarization corrections. By default
                         UVSPEC corrects for polarization corss-talk.
           'ampscalar'   When plotting amplitude, this causes it to perform
                         scalar averaging. By default it does vector averaging.
           'rms'         When plotting amplitude, this causes it to plot
                         the rms amplitude. By default it does vector averaging.
                         Ignored for xaxis=rm
           'mnoise'      When plotting noise, plot the error in the mean.
           'sdo'         Plot the difference between bin 2 and bin 1 (these
                         contain the CABB noise cal source on and off
                         autocorrelations, giving the Synchr. Detected Ouput)
                         Ignored for xaxis=rm
           'nobase'      Plot all the baselines on one plot.
           'avall'       Average all the baselines together before plotting.
           'dots'        Plot phases with dots instead of filled circles.
           'flagged'     Plot flagged data instead of unflagged data. The
                         default is to plot only unflagged data.
           'all'         Plot both flagged and unflagged data.
           'hdr'         Use high dynamic range scaling for amplitude plots:
                         log(1+amp). This works well for RFI affected data.
                         Ignored for xaxis=rm
           'timelog'     In any log file, output the time of the spectrum before
                         each spectrum is written out.

Key: axis
        This gives two strings, which determine the X and Y axes of each plot.
        The values can be abbreviated to uniqueness.
        Possible values for the X axis are:
           channel       X-axis is channel number.
           frequency     X-axis is the sky frequency, in GHz.
           dfrequency    X-axis is the Doppler-corrected frequency, in GHz.
           velocity      X-axis is velocity in radio convention, in km/sec.
           felocity      X-axis is velocity in optical convention, in km/sec.
           lag           X-axis is lag number.
           rm            X-axis is Faraday depth, in rad/m^2. When this
                         is selected, the RMTF is plotted as a dashed line,
                         and +/-1 sigma are plotted as dot-dashed lines
           lambda2       X-axis is (wavelength)^2, in m^2.
        Possible values for the Y axis are:
           amplitude     Plot amplitude.
           phase         Plot phase.
           real          Plot real part of the data.
           imaginary     Plot imaginary part of the data.
           noise         Plot the standard deviation of the data
           polang        Plot the polarisation angle of Q and U for the data
 
        The default is axis=channel,amplitude.
        If axis=rm is selected, the value input for the Y axis is ignored and
        axis=rm,real is adopted.

Key: xrange
        The min and max range along the x axis of the plot. The default
        is to autoscale.

Key: yrange
        The min and max range along the y axis of the plots. The default
        is to autoscale.

Key: device
        PGPLOT plot device/type. No default.

Key: nxy
        Number of plots in the x and y directions. The default is
        determined from the number of antennae in the data-sets.

Key: log
        Log file into which the spectra are dumped in the order in which
        they are plotted.  Really only useful if your plot is quite simple.
 
Revision: 1.17, 2018/06/25 21:08:49 UTC