Title Information
Title
A Novel Radio-Frequency Interference Flagging Technique for Radio-Interferometric Data from the Murchison Widefield Array
Type of Resource (primo)
dissertations
Name: Personal
Name Part
Kunicki, Theodora Cole
Role
Role Term: Text
creator
Name: Personal
Name Part
Pober, Jonathan
Role
Role Term: Text
Advisor
Name: Personal
Name Part
Tucker, Gregory
Role
Role Term: Text
Reader
Name: Personal
Name Part
dell'Antonio, Ian
Role
Role Term: Text
Reader
Name: Corporate
Name Part
Brown University. Department of Physics
Role
Role Term: Text
sponsor
Origin Information
Copyright Date
2024
Physical Description
Extent
16, 80 p.
digitalOrigin
born digital
Note: thesis
Thesis (Ph. D.)--Brown University, 2024
Genre (aat)
theses
Abstract
Radio-frequency interference detection and flagging is one of the most difficult and urgent problems in 21 cm Epoch of Reionization research. In this work, we present χ^2 from redundant calibration as a novel method for RFI detection and flagging, demonstrating it to be complementary to current state-of-the-art flagging algorithms. Beginning with a brief overview of radio interferometry and an overview of the Murchison Widefield Array, we then continue into a discussion of redundant calibration and the meaning of the χ^2 metric, finally demonstrating a two-step RFI flagging algorithm which uses the values of this metric to detect faint RFI. We find that roughly 27.4% of observations have RFI from digital television channel 7 detected by at least one algorithm of the three tested: 18.0% of observations are flagged by the novel χ^2 algorithm, 16.5% are flagged by SSINS, and 6.8% are flagged by AOFlagger (there is significant overlap in these percentages). Of the 27.4% of observations with detected DTV channel 7 RFI, 37.1% (10.2% of the total observations) are detected by χ^2 alone, and not by either SSINS or AOFlagger, demonstrating a significant population of as-yet undetected RFI. We find that χ^2 is able to detect RFI events which remain undetectable to SSINS and AOFlagger, especially in the domain of long-duration, weak RFI from digital television. We also discuss the shortcomings of this approach, and discuss examples of RFI which seems undetectable using χ^2 while being successfully flagged by SSINS and/or AOFlagger.
Subject (fast) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/01087390")
Topic
Radio interferometers
Subject (fast) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/01087095")
Topic
Radio--Interference
Language
Language Term (ISO639-2B)
English
Record Information
Record Content Source (marcorg)
RPB
Record Creation Date (encoding="iso8601")
20241015