eprintid: 1468933
rev_number: 31
eprint_status: archive
userid: 608
dir: disk0/01/46/89/33
datestamp: 2015-05-28 15:06:37
lastmod: 2021-09-20 00:21:19
status_changed: 2015-05-28 15:06:37
type: article
metadata_visibility: show
item_issues_count: 0
creators_name: Peck, LW
creators_name: Fenech, DM
title: SERPent: Automated reduction and RFI-mitigation software for e-MERLIN
ispublished: pub
divisions: UCL
divisions: B04
divisions: C06
note: This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike License, which permits non-commercial use, distribution, and reproduction in any medium, provided the original author and source are credited.
abstract: The Scripted E-merlin Rfi-mitigation PipelinE for iNTerferometry (SERPent) is an automated reduction and RFI-mitigation procedure utilising the SumThreshold methodology (Offringa et al., 2010a), originally developed for the LOFAR pipeline. SERPent is written in the Parseltongue language enabling interaction with the Astronomical Image Processing Software (AIPS) program. Moreover, SERPent is a simple ‘out of the box’ Python script, which is easy to set up and is free of compilers. In addition to the flagging of RFI affected visibilities, the script also flags antenna zero-amplitude dropouts and Lovell telescope phase calibrator stationary scans inherent to the e-MERLIN system.

Both the flagging and computational performances of SERPent are presented here, for e-MERLIN commissioning datasets for both L-band (1.3–1.8 GHz) and C-band (4–8 GHz) observations. RFI typically amounts to <20%–25% for the more problematic L-band observations and <5% for the generally RFI quieter C-band. The level of RFI detection and flagging is more accurate and delicate than visual manual flagging, with the output immediately ready for AIPS calibration. SERPent is fully parallelised and has been tested on a range of computing systems. The current flagging rate is at 110 GB day−1 on a ‘high-end’ computer (16 CPUs, 100 GB memory) which amounts to ∼6.9 GB CPU−1  day−1, with an expected increase in performance when e-MERLIN has completed its commissioning.

The refining of automated reduction and calibration procedures is essential for the e-MERLIN legacy projects and future interferometers such as the SKA and the associated pathfinders (MeerKAT and ASKAP), where the vast data sizes (>TB) make traditional astronomer interactions unfeasible.
date: 2013-08
official_url: http://dx.doi.org/10.1016/j.ascom.2013.09.001
vfaculties: VMPS
oa_status: green
full_text_type: pub
language: eng
primo: open
primo_central: open_green
verified: verified_manual
elements_source: crossref
elements_id: 1035620
doi: 10.1016/j.ascom.2013.09.001
lyricists_name: Fenech, Danielle
lyricists_name: Peck, Luke
lyricists_id: DFENE28
lyricists_id: LWPEC16
full_text_status: public
publication: Astronomy and Computing
volume: 2
pagerange: 54 - 66
issn: 2213-1337
citation:        Peck, LW;    Fenech, DM;      (2013)    SERPent: Automated reduction and RFI-mitigation software for e-MERLIN.                   Astronomy and Computing , 2    54 - 66.    10.1016/j.ascom.2013.09.001 <https://doi.org/10.1016/j.ascom.2013.09.001>.       Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/1468933/1/1-s2.0-S2213133713000255-main.pdf