Solar-Terrestrial Physics Solar-Terrestrial Physics Solar-Terrestrial Physics 2500-0535 44902 10.12737/stp-74202111 Results of current research Results of current research Results of current research Calibration of Siberian Radioheliograph antenna gains using redundancy Calibration of Siberian Radioheliograph antenna gains using redundancy https://orcid.org/0000-0001-9174-7350 Глоба Мария Викторовна Globa Mariia Viktorovna globa@iszf.irk.ru

аспирант физико-математических наук;

graduate student of physical and mathematical sciences;

 https://orcid.org/0009-0004-1651-1259 Лесовой Сергей Владимирович Lesovoi Sergey Vladimirovich lesovoi@iszf.irk.ru

доктор физико-математических наук;

doctor of physical and mathematical sciences;

 Институт солнечно-земной физики СО РАН Иркутск Россия Institute of Solar-Terrestrial Physics SB RAS Irkutsk Russian Federation Институт солнечно-земной физики СО РАН Иркутск Россия Institute of Solar-Terrestrial Physics SB RAS Irkutsk Russian Federation 20 12 2021 20 12 2021 7 4 98 103 02 07 2021 28 09 2021 https://zh-szf.ru/en/nauka/article/44902/view

The paper describes application of standard gain calibration using redundancy for a 48-antenna prototype of Siberian Radioheliograph. Traditionally, for calibration, the visibilities were measured only between adjacent antennas since they have the highest signal-to-noise ratio and are sufficient for phase calibration. We have shown that this limited set of visibilities did not allow using the antenna array redundancy potential and obtaining images with a high dynamic range on a permanent basis. Images without amplitude calibration contain many artifacts and require special care when analyzed. The inclusion of visibility measurement between antennas with a double step made it possible to significantly increase the accuracy of solving the system of equations for amplitudes. Images constructed using both phase and amplitude calibrations do not have visible artifacts and are more reliable.

The paper describes application of standard gain calibration using redundancy for a 48-antenna prototype of Siberian Radioheliograph. Traditionally, for calibration, the visibilities were measured only between adjacent antennas since they have the highest signal-to-noise ratio and are sufficient for phase calibration. We have shown that this limited set of visibilities did not allow using the antenna array redundancy potential and obtaining images with a high dynamic range on a permanent basis. Images without amplitude calibration contain many artifacts and require special care when analyzed. The inclusion of visibility measurement between antennas with a double step made it possible to significantly increase the accuracy of solving the system of equations for amplitudes. Images constructed using both phase and amplitude calibrations do not have visible artifacts and are more reliable.

 solar radio telescope visibility function radio interferometer gain calibration solar radio telescope visibility function radio interferometer gain calibration The work was carried out partly under Government Assignment for 2021 No. 075-00374-21-00 dated December 24, 2020 "Methods and instruments of an astrophysical experiment" (unique number 0278-2021-0010, registration number TsITiS 121040600115-2); partly using funds of the Russian Science Foundation (project No. 18-12-00172) The work was carried out partly under Government Assignment for 2021 No. 075-00374-21-00 dated December 24, 2020 "Methods and instruments of an astrophysical experiment" (unique number 0278-2021-0010, registration number TsITiS 121040600115-2); partly using funds of the Russian Science Foundation (project No. 18-12-00172)

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