Baseband Stitching: Difference between revisions

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buildmytasks
buildmytasks
</source>
</source>
Once this completes, import the task into CASA:
<source lang="python">
# In CASA
execfile('mytasks.py')
</source>
You should now be able to look at the help and parameter listings of <tt>stitch</tt>:
<source lang="python">
# In CASA
inp stitch
</source>
and
<source lang="python">
# In CASA
help stitch
</source>
== Inspecting data and choosing channel range ==
== Running <tt>stitch</tt> ==
==

Revision as of 14:26, 1 March 2012


Overview

In order to maintain constant rms noise across an observed frequency range, one may "overlap" EVLA basebands, offsetting one by 0.5 times the subband width. This way, the decreased sensitivity at subband edges can be edited out, and these frequency ranges replaced with data from the other baseband.

The contributed task stitch can be used to make this process simpler. Given a basic set of inputs, it will select channel ranges for each spectral window, which can then be used to run {split} to create a new measurement set (MS) (stitch can also run {split}, further simplifying things).

Here, we demonstrate the use of the stitch task. For information on reducing the data after running stitch, see the other CASA Guides EVLA tutorials — the data can be treated in the standard way.

Obtaining and installing stitch

First, you will need to download two files that are needed to build the task:

File:Task stitch.py File:Stitch.xml

Because of a quirk in the way Wiki stores files, you need to rename these to no longer have capitalized first letters, task_stitch.py and stitch.xml. Next, run buildmytasks to build the needed files for the task. This can either be done in CASA, or in a UNIX shell. You must be inside the directory where you have saved the files.

# In CASA
!buildmytasks

or:

# In the shell
buildmytasks

Once this completes, import the task into CASA:

# In CASA
execfile('mytasks.py')

You should now be able to look at the help and parameter listings of stitch:

# In CASA
inp stitch

and

# In CASA
help stitch

Inspecting data and choosing channel range

Running stitch

==