SINUSOID BEATING OF TWO POINT SOURCES

Here we show an example to plot the sinusoid beating amplitude from two point sources. The following lists the parameters for the two point sources contained in the UV data:

Source  1, Object type: point
  Flux (Jy):                      5.883     +/- 1.78E-06
  Offset Position (arcsec):       0.03    -1.81
  Positional errors (arcsec):     1.43E-07 1.81E-07
Source  2, Object type: point
  Flux (Jy):                      6.680     +/- 1.77E-06
  Offset Position (arcsec):       0.23    -0.27
  Positional errors (arcsec):     1.26E-07 1.59E-07

Here is the usage to plot the sinusoid beating amplitude as function of the uv distance:

  Task:   smauvamp
  vis      = /data/SMAdata/orion.model % uv file name
  axis     = vc,amp                    % axis selection
  xrange   = 0,130                     % range in the x-axis
  nbin     = 50                        % 50 bins along the x-axis
  PosA     = 7                         % rotating the uv-plane by 7 deg
                                         to match the v axis along
                                         the line connecting the two
                                         point sources.
  device   = /xs                       % plotting device 

The uv plane is rotated by 7 degree so that the transformed v-axis is in the direction along the connection line between the two point sources.

Figure: The amplitude beating for the two point sources is plotted after rotating the uv-plane by 7 degree.