Irkutsk, Irkutsk region, Russian Federation
Irkutsk, Russian Federation
Irkutsk, Russian Federation
For radio interferometers, antenna pointing accuracy is critical, as deviations in the direction of the beam from the source not only reduce the signal level, but also lead to incorrect measurements of visibility phases. These distortions cannot be corrected during data processing and reduce the dynamic range of images. The measurement method involves determining the deviation of the beam from the center of the Sun for different azimuth and elevation angles and fitting the resulting dependence using a model developed for altazimuth mounts. The model allows us to determine the deviation of the mount axis from the zenith direction, the non-orthogonality of the azimuth and elevation axes, the azimuth offset of the feed, and the azimuth and elevation constants. Mechanical adjustment of these parameters with the specified accuracy is impossible, so the correction was performed by introducing corrections to each moment in time for each antenna. Using the described technique, we managed to achieve an antenna pointing accuracy of approximately 2 arcmin.
solar radio telescope, pointing of altazimuth mounts
1. Altyntsev A.T., Lesovoi S.V., Globa M.V., et al. Multiwave Siberian Radioheliograph. Sol.-Terr. Phys. 2020, vol. 6, iss. 2, pp. 30–40. https://doi.org/10.12737/stp62202003.
2. Holleman I., Huuskonen A. Analytical formulas for refraction of radiowaves from exoatmospheric sources. Radio Sci. 2013, vol. 48, iss. 3, pp. 226–231. https://doi.org/10.1002/rds.20030.
3. de Vicente P., Barcia A. Deconstructing a pointing model for the 40M OAN radiotelescope (Technical report). 2007, 25 p. URL: https://icts-yebes.oan.es/reports/doc/IT-OAN-2007-26.pdf (accessed February 17, 2026).
4. Mangum J.G. ALMA Memo 366: A Telescope Pointing Algorithm for ALMA. 2001, 21 p. URL: https://legacy.nrao.edu/alma/memos/html-memos/alma366/memo366.pdf (accessed February 17, 2026).
5. Perley R.A. High Dynamic Range Imaging. Synthesis Imaging in Radio Astronomy II. ASP Conference Series. 1999, vol. 180, p. 275.
6. Sun Zh., Wang J., Wang G. The establishment of pointing model for the Shanghai VGOS Radio Telescope. Journal of Physics: Conference Series. 2019, vol. 1288, iss. 1, 012027. https://doi.org/10.1088/1742-6596/1288/1/012027.
7. Thompson A.R., Moran J.M, Swenson G.W., Jr. Interferometry and Synthesis in Radio Astronomy. 2nd ed. New York, Wiley, 2001, 692 p. https://doi.org/10.1002/9783527617845.
8. URL: https://ckp-rf.ru/catalog/usu/4138190/ (accessed February 17, 2026).
