System design and calibration of SITARA - A global 21 cm short spacing interferometer prototype
Global 21-cm experiments require exquisitely precise calibration of the measurement systems in order to separate the weak 21-cm signal from Galactic and extragalactic foregrounds as well as instrumental systematics. Hitherto, experiments aiming to make this measurement have concentrated on measuring...
| Main Authors: | , , , , |
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| Format: | Journal Article |
| Language: | English |
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CAMBRIDGE UNIV PRESS
2022
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| Online Access: | http://purl.org/au-research/grants/arc/FT180100321 http://hdl.handle.net/20.500.11937/91576 |
| _version_ | 1848765552912236544 |
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| author | Thekkeppattu, Jishnu McKinley, Ben Trott, Cathryn Jones, Jake Ung, Daniel |
| author_facet | Thekkeppattu, Jishnu McKinley, Ben Trott, Cathryn Jones, Jake Ung, Daniel |
| author_sort | Thekkeppattu, Jishnu |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Global 21-cm experiments require exquisitely precise calibration of the measurement systems in order to separate the weak 21-cm signal from Galactic and extragalactic foregrounds as well as instrumental systematics. Hitherto, experiments aiming to make this measurement have concentrated on measuring this signal using the single element approach. However, an alternative approach based on interferometers with short baselines is expected to alleviate some of the difficulties associated with a single element approach such as precision modelling of the receiver noise spectrum. Short spacing Interferometer Telescope probing cosmic dAwn and epoch of ReionisAtion (SITARA) is a short spacing interferometer deployed at the Murchison Radio-astronomy Observatory (MRO). It is intended to be a prototype or a test-bed to gain a better understanding of interferometry at short baselines, and develop tools to perform observations and data calibration. In this paper, we provide a description of the SITARA system and its deployment at the MRO, and discuss strategies developed to calibrate SITARA. We touch upon certain systematics seen in SITARA data and their modelling. We find that SITARA has sensitivity to all sky signals as well as non-negligible noise coupling between the antennas. It is seen that the coupled receiver noise has a spectral shape that broadly matches the theoretical calculations reported in prior works. We also find that when appropriately modified antenna radiation patterns taking into account the effects of mutual coupling are used, the measured data are well modelled by the standard visibility equation. |
| first_indexed | 2025-11-14T11:37:04Z |
| format | Journal Article |
| id | curtin-20.500.11937-91576 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T11:37:04Z |
| publishDate | 2022 |
| publisher | CAMBRIDGE UNIV PRESS |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-915762023-05-16T06:24:29Z System design and calibration of SITARA - A global 21 cm short spacing interferometer prototype Thekkeppattu, Jishnu McKinley, Ben Trott, Cathryn Jones, Jake Ung, Daniel Science & Technology Physical Sciences Astronomy & Astrophysics cosmology dark ages reionization first stars early Universe instrumentation interferometers methods data analysis cosmology observations GALACTIC RADIO-EMISSION 10 MHZ REIONIZATION EPOCH ARRAY MODEL HYDROGEN LIMITS LOFAR astro-ph.IM astro-ph.IM Global 21-cm experiments require exquisitely precise calibration of the measurement systems in order to separate the weak 21-cm signal from Galactic and extragalactic foregrounds as well as instrumental systematics. Hitherto, experiments aiming to make this measurement have concentrated on measuring this signal using the single element approach. However, an alternative approach based on interferometers with short baselines is expected to alleviate some of the difficulties associated with a single element approach such as precision modelling of the receiver noise spectrum. Short spacing Interferometer Telescope probing cosmic dAwn and epoch of ReionisAtion (SITARA) is a short spacing interferometer deployed at the Murchison Radio-astronomy Observatory (MRO). It is intended to be a prototype or a test-bed to gain a better understanding of interferometry at short baselines, and develop tools to perform observations and data calibration. In this paper, we provide a description of the SITARA system and its deployment at the MRO, and discuss strategies developed to calibrate SITARA. We touch upon certain systematics seen in SITARA data and their modelling. We find that SITARA has sensitivity to all sky signals as well as non-negligible noise coupling between the antennas. It is seen that the coupled receiver noise has a spectral shape that broadly matches the theoretical calculations reported in prior works. We also find that when appropriately modified antenna radiation patterns taking into account the effects of mutual coupling are used, the measured data are well modelled by the standard visibility equation. 2022 Journal Article http://hdl.handle.net/20.500.11937/91576 10.1017/pasa.2022.13 English http://purl.org/au-research/grants/arc/FT180100321 CAMBRIDGE UNIV PRESS fulltext |
| spellingShingle | Science & Technology Physical Sciences Astronomy & Astrophysics cosmology dark ages reionization first stars early Universe instrumentation interferometers methods data analysis cosmology observations GALACTIC RADIO-EMISSION 10 MHZ REIONIZATION EPOCH ARRAY MODEL HYDROGEN LIMITS LOFAR astro-ph.IM astro-ph.IM Thekkeppattu, Jishnu McKinley, Ben Trott, Cathryn Jones, Jake Ung, Daniel System design and calibration of SITARA - A global 21 cm short spacing interferometer prototype |
| title | System design and calibration of SITARA - A global 21 cm short spacing interferometer prototype |
| title_full | System design and calibration of SITARA - A global 21 cm short spacing interferometer prototype |
| title_fullStr | System design and calibration of SITARA - A global 21 cm short spacing interferometer prototype |
| title_full_unstemmed | System design and calibration of SITARA - A global 21 cm short spacing interferometer prototype |
| title_short | System design and calibration of SITARA - A global 21 cm short spacing interferometer prototype |
| title_sort | system design and calibration of sitara - a global 21 cm short spacing interferometer prototype |
| topic | Science & Technology Physical Sciences Astronomy & Astrophysics cosmology dark ages reionization first stars early Universe instrumentation interferometers methods data analysis cosmology observations GALACTIC RADIO-EMISSION 10 MHZ REIONIZATION EPOCH ARRAY MODEL HYDROGEN LIMITS LOFAR astro-ph.IM astro-ph.IM |
| url | http://purl.org/au-research/grants/arc/FT180100321 http://hdl.handle.net/20.500.11937/91576 |