Ntsikelelo Charles
A5006030280- Radio Astronomy Observations and Technology
- Antenna Design and Optimization
- Astrophysics and Cosmic Phenomena
- Radio Wave Propagation Studies
- Microwave Engineering and Waveguides
- Millimeter-Wave Propagation and Modeling
- Superconducting and THz Device Technology
- GNSS positioning and interference
- Soil Moisture and Remote Sensing
- Electromagnetic Compatibility and Measurements
North-West University
2024
Rhodes University
2022-2023
ABSTRACT Precision antenna calibration is required for mitigating the impact of foreground contamination in 21 cm cosmological radio surveys. One widely studied source error effect missing point sources sky model; however, poorly understood diffuse galactic emission also creates a bias that can complicate clean separation foregrounds from signal. In this work, we present technique suppressing with temporal filtering interferometric visibilities observed drift-scan mode. We demonstrate on...
The 21 cm transition from neutral Hydrogen promises to be the best observational probe of Epoch Reionisation (EoR). This has led construction low-frequency radio interferometric arrays, such as Reionization Array (HERA), aimed at systematically mapping this emission for first time. Precision calibration, however, is a requirement in observations. Due spatial compactness HERA, array prone effects mutual coupling, which inevitably lead non-smooth calibration errors that contaminate data. When...
The 21~cm transition from neutral Hydrogen promises to be the best observational probe of Epoch Reionisation. main difficulty in measuring 21 cm signal is presence bright foregrounds that require very accurate interferometric calibration. Closure quantities may circumvent calibration requirements but be, however, affected by direction dependent effects, particularly antenna primary beam responses. This work investigates impact beams mutual coupling on closure phase and its power spectrum....
ABSTRACT The 21 cm transition from neutral Hydrogen promises to be the best observational probe of Epoch Reionization (EoR). This has led construction low-frequency radio interferometric arrays, such as Array (HERA), aimed at systematically mapping this emission for first time. Precision calibration, however, is a requirement in observations. Due spatial compactness HERA, array prone effects mutual coupling, which inevitably lead non-smooth calibration errors that contaminate data. When...
ABSTRACT Radio interferometers aiming to measure the power spectrum of redshifted 21 cm line during Epoch Reionization (EoR) need achieve an unprecedented dynamic range separate weak signal from overwhelming foreground emissions. Calibration inaccuracies can compromise sensitivity these measurements effect that a detection EoR is precluded. An alternative standard analysis techniques makes use closure phase, which allows one bypass antenna-based direction-independent calibration. Similarly...
Precision antenna calibration is required for mitigating the impact of foreground contamination in 21 cm cosmological radio surveys. One widely studied source error effect missing point sources sky model; however, poorly understood diffuse galactic emission also creates a bias that can complicate clean separation foregrounds from signal. In this work, we present technique suppressing with temporal filtering interferometric visibilities observed drift-scan mode. We demonstrate on mock...
Radio interferometers aiming to measure the power spectrum of redshifted 21 cm line during Epoch Reionisation (EoR) need achieve an unprecedented dynamic range separate weak signal from overwhelming foreground emissions. Calibration inaccuracies can compromise sensitivity these measurements effect that a detection EoR is precluded. An alternative standard analysis techniques makes use closure phase, which allows one bypass antenna-based direction-independent calibration. Similarly...