CALIBRATION OF SIBERIAN RADIOHELIOGRAPH ANTENNA GAINS USING REDUNDANCY
Abstract and keywords
Abstract (English):
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.

Keywords:
solar radio telescope, visibility function, radio interferometer, gain calibration
Text
Publication text (PDF): Read Download
References

1. 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:https://doi.org/10.12737/stp-62202003.

2. 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. 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:https://doi.org/10.1023/A:1026153410061.

4. Hjellming R.M., Basart J.P. The theory of the instrument. Introduction to the NRA0 Very Large Array. Ch. 2. NRAO, 1982.

5. Högbom J.A. Aperture synthesis with a non-regular distribution of interferometer baselines. Astron. Astrophys. Suppl. 1974, vol. 15, p. 417.

6. Lesovoi S.V., Altyntsev A.T., Ivanov E.F. Gubin A.V. The multifrequency Siberian Radioheliograph. Solar Phys. 2012, vol. 280, iss. 2, pp. 651–661. DOI:https://doi.org/10.1007/s11207-012-0008-7.

7. Lesovoi S., Altyntsev A., Kochanov A., Grechnev V., Gubin A., Zhdanov D., et al. Siberian Radioheliograph: first results. Solar Terrestrial Physics. 2017, vol. 3, iss. 1, pp. 3–18. DOI:https://doi.org/10.12737/24347.

8. Liu A., Tegmark M., Morrison S., Lutomirski A., Zaldarriaga M. Precision Calibration of Radio Interferometers Using Redundant Baselines. 2010. arXiv:1001.5268. DOI:https://doi.org/10.1111/j. 1365-2966.2010.17174.x.

9. Nakajima H., Nishio M., Enome S., et al. The Nobeyama Radioheliograph. Proc. IEEE. 1994, vol. 82, iss. 5, pp. 705–713.

10. Noordam J., de Bruyn A. High dynamic range mapping of strong radio sources, with application to 3C84. Nature. 1982, vol. 299, iss. 5884, pp. 597–600. DOI:https://doi.org/10.1038/299597a0.

11. Perley R.A. High Dynamic Range Imaging. Synthesis Imaging in Radio Astronomy II, A Collection of Lectures from the Sixth NRAO/NMIMT Synthesis Imaging Summer School. ASP Conference Ser., 1999, vol. 180, pp. 275.

12. Thompson A.R., Moran J.M, Swenson G.W., Jr.. Interferometry and Synthesis in Radio Astronomy. 2nd ed. New York: Wiley, 2001. 692 p. DOI:https://doi.org/10.1002/9783527617845.

13. Wieringa M.H. An investigation of the telescope based on calibration methods ‘redundancy’ and ‘self-cal’. Experimental Astronomy. 1992, vol. 2, pp. 203–225. DOI: 10.1007/ BF00420576.

Login or Create
* Forgot password?