中国科学院南京天文光学技术研究所机构知识库

SiTian is an ambitious ground-based all-sky optical monitoring project, developed by the Chinese Academy of Sciences. The concept is an integrated network of dozens of 1-m-class telescopes deployed partly in China and partly at various other sites around the world. The main science goals are the detection, identification and monitoring of optical transients （such as gravitational wave events, fast radio bursts, supernovae） on the largely unknown timescales of less than 1 day; SiTian will also provide a treasure trove of data for studies of AGN, quasars, variable stars, planets, asteroids, and microlensing events. To achieve those goals, SiTian will scan at least 10,000 square deg of sky every 30 min, down to a detection limit of V21 mag. The wide field of view optical system for SiTian Project, known as SiTian optical system, is characterized in that the catadioptric telescope optical system includes an aspheric corrector plate A with a central hole, a spherical or aspheric reflective primary mirror B, a spherical lens C, a spherical lens D, a spherical lens E, an optical filter F, a camera window G and a focal plane H, which are arranged in sequence along the incident direction of light from front to back. Specifically, the aspheric plate A with a central hole is annular, and the diameter of the central hole is approximately the maximum lens diameter of the corrector lens group. Located at the position of the optical system aperture stop, it is used to correct the spherical aberration of the spherical or aspherical reflection primary mirror. An optical system with a large field of view and excellent image quality is disclosed in the invention, which belongs to the transformation of Schmidt telescopes. In addition, its primary mirror diameter is smaller than the traditional Schmidt telescopes, while meeting the same optical parameters. In the present invention, the camera is outside the lens tube, and there is no heat source in the lens tube, so the optical image quality will not be affected; the length of the lens tube is reduced by half; and the flat image surface has excellent image quality and uniform throughout the whole field of view.1/3 FIGURES Figure 1A schematic diagram of the optical structure of the invention. B ---r-----Figure 2The structural diagram of the optical system of Embodiment 1. e a ySpot Diagram 60c modi-.chmidt 7dqege21nzm Figure 3A full field image spot diagram （450-550nm band range） of Embodiment 1.