Thursday 29 January 2009

Bayesian retrieval of water vapour column

This week I've been in part working on Bayesian retrieval of water vapour column from prototype WVR data.

The attached plot shows a typical result: It shows the retrieved *zenith* water vapour column as a function of time while the telescope was tracking a source for about an hour (it was setting at the time). The colour scale represents the posterior distribution and is hence an indication of the confidence in the retrieved values.

You can find out more detail on the retrieval method in my most recent talk at these web pages:

http://www.mrao.cam.ac.uk/~bn204/publications/publicationlist.html

Thursday 22 January 2009

casa-core

I've recently tried to build casa-core (http://casacore.googlecode.com) and found that it is surprisingly easy to build on my laptop system (Ubuntu/8.10 32bit). In fact, the only configuration item that required any fiddling was the build of the WCS library. The main gripe is excessively long compilation time.

In order to make management of the casa-core source more flexible, I used the bazaar version control system (http://bazaar-vcs.org/) and the bzr-svn plugin to check-out the casa-core source code. This allows some significant advantages compared to plain SVN :

* Access to full history information without connection to the
internet

* Ability to make local branches

* Ability to layer local changes on top of the revisions contained in
the SVN

If you want to know more, feel free to write to me...

We will be using casa-core to, at the very least, access Measurement Set data produced by ALMA.

Wednesday 14 January 2009

Monday 12 January 2009

Visiting NRAO/Charlottesville

For the first part of this week I'm visiting NRAO Charlottesville offices: http://www.nrao.edu/

Wednesday 7 January 2009

Talk at the URSI NA meeting in Boulder

I gave a talk about ALMA phase correction and calibration at the URSI
meeting in Boulder. The PDF is available from the usual place:

http://www.mrao.cam.ac.uk/~bn204/publications/2009/NikolicURSI09.pdf