[ Basic Info | References | User Guide ]
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.
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 polarizatiopn 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.
'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.
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.
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.
The default is axis=channel,amplitude.
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.