What astronomical knowledge is described in Tian Wenzhi of Sui Shu?

Sui Shuzhi, Li Zhu. Sui Zhi elaborated the structure and track of the armillary sphere in detail, and recorded for the first time the armillary sphere cast by Zhao Hulan Courting before the Northern Wei Dynasty, which left valuable information for the structure of the early armillary sphere. "Sui Shu" also discusses the coverage, ground, landscape, leakage and other contents of the map, and records the system of 10 o'clock in the day and 5 o'clock at night. The results of photogrammetry in Jiaozhou, Jinling and Luoyang are listed for the first time, and it is pointed out that the statement that "an inch is separated by thousands of miles" is not true. The book also quoted Jiang Ji's discovery that "at the beginning of a day, there is air in the ground, so the color is red and big, and there is no air in the sky, so the color is white and small", which is in line with the reason of poor air. He also quoted Zhang Zixin's observation on the island for many years, and found that the movement of the sun is fast and slow, and the movement of the planets is uneven, and put forward the reasons that inspired him to explain. These are all important discoveries in the history of astronomy in China.