Research on fine co-focus adjustment method for segmented solar telescope

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Détails bibliographiques
Auteurs principaux:	Wang, Kunyan, Dai, Yichun, Wang, Bin, Tan, Xu, Yang, Dehua, Jin, Zhenyu
Format:	Preprint
Publié:	2024
Sujets:	Instrumentation and Methods for Astrophysics
Accès en ligne:	Acceder al recurso
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_version_	1866914749310042112
author	Wang, Kunyan Dai, Yichun Wang, Bin Tan, Xu Yang, Dehua Jin, Zhenyu
author_facet	Wang, Kunyan Dai, Yichun Wang, Bin Tan, Xu Yang, Dehua Jin, Zhenyu
contents	For segmented telescopes, achieving fine co-focus adjustment is essential for realizing co-phase adjustment and maintenance, which involves adjusting the millimeter-scale piston between segments to fall within the capture range of the co-phase detection system. CGST proposes using a SHWFS for piston detection during the co-focus adjustment stage. However, the residual piston after adjustment exceeds the capture range of the broadband PSF phasing algorithm$(\pm 30 μm) $, and the multi-wavelength PSF algorithm requires even higher precision in co-focus adjustment. To improve the co-focus adjustment accuracy of CGST, a fine co-focus adjustment based on cross-calibration is proposed. This method utilizes a high-precision detector to calibrate and fit the measurements from the SHWFS, thereby reducing the impact of atmospheric turbulence and systematic errors on piston measurement accuracy during co-focus adjustment. Simulation results using CGST demonstrate that the proposed method significantly enhances adjustment accuracy compared to the SHWFS detection method. Additionally, the residual piston after fine co-focus adjustment using this method falls within the capture range of the multi-wavelength PSF algorithm. To verify the feasibility of this method, experiments were conducted on an 800mm ring segmented mirror system, successfully achieving fine co-focus adjustment where the remaining piston of all segments fell within $\pm 15 μm$.
format	Preprint
id	arxiv_https___arxiv_org_abs_2404_07787
institution	arXiv
publishDate	2024
record_format	arxiv
spellingShingle	Research on fine co-focus adjustment method for segmented solar telescope Wang, Kunyan Dai, Yichun Wang, Bin Tan, Xu Yang, Dehua Jin, Zhenyu Instrumentation and Methods for Astrophysics For segmented telescopes, achieving fine co-focus adjustment is essential for realizing co-phase adjustment and maintenance, which involves adjusting the millimeter-scale piston between segments to fall within the capture range of the co-phase detection system. CGST proposes using a SHWFS for piston detection during the co-focus adjustment stage. However, the residual piston after adjustment exceeds the capture range of the broadband PSF phasing algorithm$(\pm 30 μm) $, and the multi-wavelength PSF algorithm requires even higher precision in co-focus adjustment. To improve the co-focus adjustment accuracy of CGST, a fine co-focus adjustment based on cross-calibration is proposed. This method utilizes a high-precision detector to calibrate and fit the measurements from the SHWFS, thereby reducing the impact of atmospheric turbulence and systematic errors on piston measurement accuracy during co-focus adjustment. Simulation results using CGST demonstrate that the proposed method significantly enhances adjustment accuracy compared to the SHWFS detection method. Additionally, the residual piston after fine co-focus adjustment using this method falls within the capture range of the multi-wavelength PSF algorithm. To verify the feasibility of this method, experiments were conducted on an 800mm ring segmented mirror system, successfully achieving fine co-focus adjustment where the remaining piston of all segments fell within $\pm 15 μm$.
title	Research on fine co-focus adjustment method for segmented solar telescope
topic	Instrumentation and Methods for Astrophysics
url	https://arxiv.org/abs/2404.07787

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