1.iii: Loading some bookmarks

Logged on 07/09/2009 04:43:10 PM

Before we view the MS we have to load a few bookmarks. These are pre-defined in the TDL script to allow visualisation of certain nodes in the tree.

With the runtime options window still open you can select these from the bookmarks menu (see screen grab below).

Select 'inspect input visibilities' and one of the 'by baseline' options, then select 'view MS'. If you've closed the runtime options window by mistake then just click the 'TDL Exec' button in the toolbar.

You should see a few plots appearing in the 'Gridded Viewers' section. The 'viewers' screen grab below shows the 'by baseline' results.

What you can see here are the amplitude (left) and phase (right) as a function of time (y-axis) and frequency (x-axis), with the colour scale indicating the value.

Note how the phases are completely flat. This is consistent with a single point source at the phase centre. The variation in the amplitudes is due to the random antenna based gain errors we included. Of course, we have the benefit of knowing exactly what went into the simulation here, but examining visibilities in this way can tell you a lot about the source structure without making an image.

This is a good habit to get into.

If you click the 'inspect input visibilities' tab you will see the amplitude versus time for each baseline, also shown below in the 'inspector' screen shot. If you right-click on the plot you can choose phases with the 'complex data selection' option. You can also zoom by drawing boxes. If you middle click on one of the plots it will pop out into a separate window.

Just play around, you'll get the hang of it.

Data products

calico-view-ms-bookmarks.png

calico-view-ms-bookmarks.png

calico-view-ms-viewers.png

calico-view-ms-viewers.png

calico-view-ms-inspector.png

calico-view-ms-inspector.png