标题： 太阳轨道器上 PHI/HRT 的波前误差在各种日心距离下的变化 显示英文标题

标题： Wavefront error of PHI/HRT on Solar Orbiter at various heliocentric distances

摘要： 我们使用波前探测技术来表征太阳轨道器（SO）常规任务阶段第二次遥感窗口期间，极化与日震成像仪（SO/PHI）高分辨率望远镜（HRT）数据产品的图像质量。我们的最终目标是通过与HRT点扩散函数（PSF）进行去卷积来重建HRT数据，并纠正光学畸变对数据的影响。我们利用一组聚焦和离焦图像来计算波前误差，并通过相位多样性（PD）分析推导出HRT的PSF。HRT的波前误差取决于太阳轨道器到太阳的距离。在距离为$>0.5$天文单位时，波前误差较小，主要来源于HRT的固有光学特性。在距离为$<0.5$天文单位时，热光学效应的热量排斥入射窗（HREW）变得明显。我们开发了一种插值方案，用于描述波前误差随太阳轨道器到太阳距离的热变化而变化。我们还引入了一种新的图像重建层次，称为“畸变校正”，旨在减少图像去卷积引起的噪声，同时消除由HREW引起的畸变。通过相位多样性计算得到的PSF显著减少了近日点HRT数据中由HREW引起的退化。此外，畸变校正相比通常的PD重建所导致的噪声增加因子$3$，其噪声增加因子仅为$1.45$。 显示英文摘要

摘要： We use wavefront sensing to characterise the image quality of the the High Resolution Telescope (HRT) of the Polarimetric and Helioseismic Imager (SO/PHI) data products during the second remote sensing window of the Solar Orbiter (SO) nominal mission phase. Our ultimate aims are to reconstruct the HRT data by deconvolving with the HRT point spread function (PSF) and to correct for the effects of optical aberrations on the data. We use a pair of focused--defocused images to compute the wavefront error and derive the PSF of HRT by means of a phase diversity (PD) analysis. The wavefront error of HRT depends on the orbital distance of SO to the Sun. At distances $>0.5$\,au, the wavefront error is small, and stems dominantly from the inherent optical properties of HRT. At distances $<0.5$\,au, the thermo-optical effect of the Heat Rejection Entrance Window (HREW) becomes noticeable. We develop an interpolation scheme for the wavefront error that depends on the thermal variation of the HREW with the distance of SO to the Sun. We also introduce a new level of image reconstruction, termed `aberration correction', which is designed to reduce the noise caused by image deconvolution while removing the aberrations caused by the HREW. The computed PSF via phase diversity significantly reduces the degradation caused by the HREW in the near-perihelion HRT data. In addition, the aberration correction increases the noise by a factor of only $1.45$ compared to the factor of $3$ increase that results from the usual PD reconstructions.