Affiliation:
1. Institute of Solar Terrestrial Physics SB RAS
Abstract
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.
Publisher
Infra-M Academic Publishing House
Reference13 articles.
1. Алтынцев А.Т., Лесовой С.В., Глоба М.В. и др. Многоволновый Сибирский радиогелиограф. Солнечно-земная физика. 2020. Т. 6, № 2. С.37–50. DOI: 10.12737/szf-62202003., Altyntsev A., Lesovoi S., Globa M., Gubin A., Kochanov A., Grechnev V., et al., Multiwave Siberian Radioheliograph. Solar-Terrestrial Physics. 2020, vol. 6, iss. 2, pp. 30–40. DOI: 10.12737/stp-62202003.
2. Лесовой С.В., Алтынцев А.Т., Кочанов А.А. и др. Сибирский радиогелиограф: первые результаты. Солнечно-земная физика. 2017. Т. 3, № 1. С. 3–16. DOI: 10.12737/24347., Cornwell T., Fomalont E.B. Self-calibration. Synthesis imaging in radio astronomy. A Collection of Lectures from the Third NRAO Synthesis Imaging Summer School. Published by the Astronomical Society of the Pacific. 1989, vol. 6, p. 185. San Francisco, 1989.
3. Томпсон А.Р., Моран Дж.М., Свенсон Дж.У., мл. Интерферометрия и синтез в радиоастрономии. М.: Мир, 1989. 568 с., Grechnev V.V., Lesovoi S.V., Smolkov G.Ya., et al. The Siberian Solar Radio Telescope: the current state of the instrument, observations, and data. Solar Phys. 2003, vol. 216, iss. 1, pp. 239–272. DOI: 10.1023/A:1026153410061.
4. Cornwell T., Fomalont E.B. Self-calibration. Synthesis imaging in radio astronomy. A Collection of Lectures from the Third NRAO Synthesis Imaging Summer School. Published by the Astronomical Society of the Pacific. Vol. 6. P. 185. San Francisco, 1989., Hjellming R.M., Basart J.P. The theory of the instrument. Introduction to the NRA0 Very Large Array. Ch. 2. NRAO, 1982.
5. Grechnev V.V., Lesovoi S.V., Smolkov G.Ya., et al. The Siberian Solar Radio Telescope: the current state of the instrument, observations, and data. Solar Phys. 2003. Vol. 216, iss. 1. P. 239–272. DOI: 10.1023/A:1026153410061., Högbom J.A. Aperture synthesis with a non-regular distribution of interferometer baselines. Astron. Astrophys. Suppl. 1974, vol. 15, p. 417.