Reducing CABB Data

An example

This page will walk through the reduction process for the ToO observation CX167, which was observed on 16 Feb 2009 with the interim CABB system. This system had 5 antenna dual pol, 1 IF at 6/3cm, but not all 2048 continuum channels were working.

First, make sure you have the CABB version of MIRIAD, otherwise this will not work!

To do this on kaputar, make sure that /nfs/atapplic/miriad-cabb/linux64/bin is in your path ahead of any other MIRIAD directories. To check that this is so, in a terminal, type which atlod. It should return /nfs/atapplic/miriad-cabb/linux64/bin/atlod.

Then source /nfs/atapplic/miriad-cabb/MIRRC. You should now be using the CABB version of MIRIAD.

To begin with, the reduction is the same as any other pre-CABB dataset, and we start by using ATLOD to read in the data. We have four files for CX167: 2009-02-16_0658.CX167, 2009-02-16_0701.CX167, 2009-02-16_1651.CX167 & 2009-02-16_1824.CX167.

atlod in=*.CX167 out=cx167.uv ifsel=2 options=birdie

Here, we use ifsel=2 because only 1 IF was available with the interim CABB system and it was written as IF 2.

At this point, we can see what the CABB spectrum looks like with uvspec:

uvspec vis=cx167.uv "select=pol(xx,yy)" interval=10 options=nobase,avall axis=chan,amp device=/xs

We obviously need to calibrate the bandpass. Luckily there is some 1934-638 data, so we calibrate our bandpass with that:

mfcal vis=cx167.uv "select=source(1934-638)" interval=0.1

Giving the same uvspec command as before we now get: