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dc.contributor.advisorOozeer, N.
dc.contributor.advisorBassett, B.
dc.contributor.advisorLoubser, I.
dc.contributor.authorSaharin, M.R.
dc.date.accessioned2018-10-08T13:35:18Z
dc.date.available2018-10-08T13:35:18Z
dc.date.issued2018
dc.identifier.urihttps://orcid.org/0000-0002-3807-1205
dc.identifier.urihttp://hdl.handle.net/10394/31291
dc.descriptionMasters in Space Physics, North-West University, Potchefstroom Campus
dc.description.abstractRadio interferometers are used for polarimetric imaging. This is one of the types of studies that will be done at the Southern African MeerKAT telescope and in turn, the Square Kilometre Array (SKA) telescope. The polarization of the radiation coming to the interferometer from an astronomical source can be altered by any magneto-ionic plasma along the line-of-site, whether the plasma is associated with the source itself or it is separate from the source. However, the polarization of the radiation that is measured is altered by the ionosphere due to Faraday rotation. We therefore need to remove the e ects of this ionospheric Faraday rotation. Unfortunately, this is made di cult by the variability of the ionosphere due to space weather. Therefore, the relationship between the total electron content (TEC) of the ionosphere and the ionospheric Faraday rotation needs to be determined. O'Sullivan et al. [2012] showed that modelling the polarization angle and the degree of polarization dependences with wavelength squared is vital in measuring the true Faraday depth structure of extragalactic radio sources. This project aimed to extend the methods used by O'Sullivan et al., and potentially other methods, to extract Faraday rotation parameters from existing KAT-7 and MeerKAT data and to make progress towards linking these parameters to the change in TEC of the ionosphere over the SKA site in the Karoo. Three KAT-7 observations and one MeerKAT commissioning observation were agged and calibrated, during which the calibration procedures and results were studied in detail, including polarization calibration. The Stokes Q and U parameters, which describe the polarization properties, were extracted. Three di erent outlier detection methods were compared and used to remove the outliers in the Q and U data. Di erent polarization models were then tted to the Q and U data, to extract the rotation measure (RM) properties of the sources. The rst KAT-7 observation showed that 3C286 was best described by a three RM-component model. The other two KAT-7 observations and the MeerKAT observation all showed that 3C138 was also best described by a three RM-component model. The time-variabilities of the polarization properties of these sources were analysed and compared to total electron content (TEC) data from a nearby TrigNet station, as well as the change in TEC (dTEC). We could not come to an exact conclusion about the relationship between the ionosphere properties and the rotation measure since these observations were not carried out within the same time window or the data from surrounding TrigNet stations were missing. We showed that there is scope for such a multi-instrument analysis and this can be coordinated and carried out in the future with the SKA path nder, MeerKAT.en_US
dc.language.isoenen_US
dc.publisherNorth-West Universityen_US
dc.subjectFaraday rotationen_US
dc.subjectionosphereen_US
dc.subjecttotal electron contenten_US
dc.subjectrotation measureen_US
dc.subjectpolarizationen_US
dc.subjectKAT-7en_US
dc.subjectMeerKATen_US
dc.subjectSKAen_US
dc.subjectradio astronomyen_US
dc.subjectcalibrationen_US
dc.subjectpolarimetryen_US
dc.subjectoutlier detectionen_US
dc.subjectTrigNeten_US
dc.titleA multi-instrument ionospheric Faraday rotation analysisen_US
dc.typeThesisen_US
dc.description.thesistypeMastersen_US
dc.contributor.researchID24287717 - Oozeer, Nadeem (Supervisor)


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