Processing e-MERLIN data with the pipeline
The e-MERLIN pipeline is written in Python and uses the ParselTongue interface to AIPS. You will need all of these installed in order to use it. Download the latest versions of the e-MERLIN pipeline and the SERPent flagger from GitHub.
Please note that we are still developing the pipeline. The current public release (v0.7) will process, calibrate and image a standard continuum dataset containing observations of 3C286, OQ208, a source and its associated phase calibrator. The calibration follows that described in the cookbook, but it is not intelligent and is unlikely to produce paper-ready images. If you calibrate your data using the pipeline, we advise you to edit your solutions manually, and inspect the plots produced, and your results, carefully.
The code is now archived publicly at GitHub and you should download it from there. It also has an entry in the Astrophysics Source Code Library (ascl:1407.017) and has a doi (for v0.7: 10.5281/zenodo.10163). The description paper was published in the Journal of Open Research Software (and on astro-ph); if you make use of the pipeline in your research, please include a reference to the pipeline paper when you publish it.
The pipeline requires the following files:
- eMERLIN_tasks.py - the task definitions
- eMERLIN_pipeline.py - the pipeline script
- doall_inputs - an example inputs script which is required to drive the operation of the pipeline
- flagmask512.fg - a flag mask for the worst of the known RFI (applied if doflagmask=1 in the inputs file)
There is now a cookbook (see the support pages for details) describing the procedures for reduction of e-MERLIN data, including more detailed descriptions of the pipeline operation and recommended parameters. Any comments, feedback or bug reports should be sent to the e-MERLIN team at email@example.com.
Test data: for the purposes of verification, test datasets are available. They was observed for use by students at the first e-MERLIN data reduction school, held at JBCA in early 2014. There are L-band (104MB) and C-band (15GB) observations of the gavitational lens system B1938+666, plus an associated phase calibrator, together with scans on the standard e-MERLIN calibrators 3C286 (1331+305) and OQ208 (1407+284).
You may find the AIPS helpsheet useful (plain text, pdf), originally written for students in the MSc room at Jodrell, undertaking the Radio Interferometry course and using AIPS for the first time. It is intended as a memory aid, not a tutorial. If you need more help, try the AIPS cookbook over at NRAO, or the old MERLIN User Guide (the MUG) instead as it contains a lot of useful information, or you could work through Hans-Rainer Klockner's excellent AIPS tutorial.