中国科学院光电技术研究所机构知识库

地基大口径望远镜在观测的过程中，成像质量会受到镜面失调误差的影响。镜面失调误差会导致望远镜的成像质量下降、观测精度降低，使望远镜无法达到技术指标，无法准确的观测天体和空间碎片。因此，需要采用像差检测技术对望远镜的像差进行检测，并通过像差校正方法来减小镜面失调量，使望远镜处于最佳的工作状态。

本文的研究对象是2.5米口径、3°视场的主焦望远镜，希望能采用一种无需额外添加光学元件的像差检测方法，通过相应的校正方法校正光学元件的失调误差。具体工作如下：

1. 研究了分裂式曲率传感器的像差检测方法。由于望远镜内部具有空间限制，无法在光学系统内部添加额外的光学元件。因此需要添加分光元件的传统曲率传感器方法不再适用。对曲率传感器方法进行改进，采用分裂式曲率传感器的方法，可以在仅使用拼接CCD的条件下进行检测。解决了大口径望远镜内部空间限制的问题。
2. 设计了300mm口径，0.6°视场的卡塞格林系统，用于验证像差校正方法能否适用于不同种类的光学系统。
3. 研究了两步式灵敏度矩阵法的像差校正方法。传统的灵敏度矩阵法精度较低，通过改进灵敏度函数的计算方法、泽尼克系数的选用原则和校正次数，提高了校正精度，并用两步式灵敏度矩阵法对卡塞格林系统和2.5米口径，3°视场的光学系统进行校正，证明了两步式灵敏度矩阵法可以解决镜面失调量校正的问题且具有足够的精度。

The imaging quality of ground-based large-aperture telescopes is affected by mirror misalignment errors during observation. The mirror misalignment error will lead to the decline of imaging quality and observation accuracy of the telescope, which makes it impossible for the telescope to reach the technical targets and to observe celestial bodies and space debris accurately. Therefore, aberration detection technology is needed to detect the aberration of the telescope, and aberration correction method is used to reduce the mirror misalignment, so that the telescope is in the best working state.

The object of this paper is a catadioptric telescope with 2.5m aperture and 3 degree field of view. It is hoped that an aberration detection method without additional optical elements can be used to correct the misalignment error of optical elements by corresponding correction methods. The specific work is as follows:

    1.The aberration detection method of split curvature sensor is studied. Because of the space limitation inside the telescope, it is impossible to add additional optical elements in the optical system. Therefore, the traditional curvature sensor method which needs to add spectroscopic elements is no longer applicable. The method of curvature sensor is improved. The split curvature sensor can be used to detect the curvature only by splicing CCD. The problem of space limitation in large aperture telescope is solved.

    2.The Cassegrain system with 300 mm aperture and 0.6 degree field of view is designed to verify whether the aberration correction method can be applied to different kinds of optical systems.

    3.The aberration correction method of two-step sensitivity matrix method is studied. The accuracy of traditional sensitivity matrix method is low. The correction accuracy is improved by improving the calculation method of sensitivity function, the selection principle of Zernike coefficient and the number of times of correction. The two-step sensitivity matrix method is used to correct the Cassegrain system and the optical system with 2.5m aperture and 3 degree field of view. It is proved that the two-step sensitivity matrix method can solve the correction of mirror misalignment. The problem has sufficient accuracy.