Capabilities for detection of sunspot edges on Shack–Hartmann sensor images: application of the Canny method

Driga M.B., Shikhovtsev A.Y., Kovadlo P.G.

For Russian citation (Opticheskii Zhurnal):

Дрига М.Б., Шиховцев А.Ю., Ковадло П.Г. Возможности обнаружения краёв солнечных пятен по изображениям, полученным с помощью датчика Шэка–Гартмана: применение метода Кенни // Оптический журнал. 2025. Т. 92. № 6. С. 77–86. http://doi.org/10.17586/1023-5086-2025-92-06-77-86

Driga M.B., Shikhovtsev A.Yu., Kovadlo P.G. Capabilities for detection of sunspot edges on Shack–Hartmann sensor images: application of the Canny method [in Russian] // Opticheskii Zhurnal. 2025. V. 92. № 6. P. 77–86. http://doi.org/10.17586/1023-5086-2025-92-06-77-86

For citation (Journal of Optical Technology):

Abstract:

Study subject. Optical distortions on the telescope aperture are formed due to the atmospheric turbulence along the line of sight. The aim of this paper is to study the possibilities of using computer vision methods to determine the contours of sun-spots measured by the Shack–Hartmann sensor, as well as to develop approaches to estimate the shift of the solar image in the plane conjugate with the telescope aperture. Methods. The Canny method is used to determine the contours and amplitudes of the shift of the solar image of sunspot images recorded using the Shack–Hartmann sensor. The Fried parameter for the Large Solar Vacuum Telescope is estimated based on the variance of differential sunspot shifts calculated using the Canny edge detection method. Main results. The paper applies computer vision methods and algorithms to process subimages obtained using the Shack–Hartmann sensor. The proposed edge detection and estimating Fried parameter algorithms were adapted and applied to the Large Solar Vacuum Telescope. Practical significance. The computer vision methods developed in the work can be used in applications for adaptive optics systems, as well as for the improvment of measuring methods of atmospheric optical turbulence profiles.

Keywords:

adaptive optics system, Shack–Hartmann sensor, Canny method, optical turbulence, atmospheric distortions, computer vision

Acknowledgements:

the study was supported by the grant of the Russian Science Foundation № 24-72-10043, https://rscf.ru/project/24-72-10043/. The results of measurements of the charac-teristics of optical distortions were obtained using the Unique Scientific Installation Large Solar Vacuum Telescope http://ckp-rf.ru/usu/200615/

OCIS codes: 280.4788, 010.1330

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