China is an ancient civilization in the world. Due to the needs of life and production, the measurement work started very early. During the Spring and Autumn Period and the Warring States Period, a quarter calendar was compiled, with a year of 365.25 days, which is the same as the Julian calendar adopted by the Romans, but four times earlier. Five hundred years ago, the synodic month measured by Zu Chongzhi in the Southern and Northern Dynasties was 29.530588 days, which was only 0.3 seconds away from the current value. The “Tongtian Calendar” compiled by Yang Zhongfu in the Song Dynasty has a year of 365.2425 days. Compared with the modern value, there is only a 26-second error. The reason why such accurate data can be obtained is that the armillary sphere was created in the fourth century BC, and it was used to measure The coordinates of the celestial body and the extreme. Zhang Heng of the Han Dynasty improved the armillary sphere, and wrote “the armillary sphere illustration”. In the Yuan Dynasty, Guo Shoujing improved the armillary sphere into a simple one. The instruments used for astronomical observation include the Gui, the watch, and the complex moment. The instruments used for timing include the clepsydra and the sundial, etc.
In terms of map surveying and mapping, due to the need for marching and combat, the emperors of the past dynasties The earliest recorded ancient map is the topographic map near the Luoyi city site in the early Western Zhou Dynasty. Maps in the Zhou Dynasty were widely used, and the officials who managed the maps had a very fine division of labor. The earliest ancient map that can be seen now is Changsha. The map of Zhanchangsha and the garrison map unearthed from Mawangdui Tomb №3 and buried in 168 BC contain mountains, rivers, settlements, roads, and military elements. China can draw high-level maps in the past dynasties, which is related to surveying. The development of technology is related. The tools for measuring length in ancient China include poles, measuring ropes, walking carts, and drum carts; instruments and tools for measuring elevation include moment and level; instruments for measuring direction are hope cylinder and compass. Development is closely related to mathematical knowledge. The “Zhou Bi Suanjing” and “Nine Chapter Arithmetic” which came out before BC both use similar triangles to measure. Two, three, or even four measurements were carried out on the zhang pole to solve the example of mountain height and river width, which greatly promoted the development of measurement technology. In addition to the compilation of calendars and mapping maps, the achievements of surveying and mapping in ancient China include: a group of monks in the Tang Dynasty Under the auspices of Henan, the distance from Baima, Henan, through Junyi, Fugou to Shangcai and the height of the North Pole were measured, and the arc length at one degree of the meridian was 132.31KM, which contributed to the correct understanding of the earth for human beings. After the founding of the People’s Republic of China, China’s surveying and mapping industry has made great progress. Established and unified — — National coordinate system and elevation system; established a nationwide geodetic control network, national leveling network, basic gravity network, and satellite Doppler network; completed the overall adjustment of the national geodetic network and leveling network; completed the surveying and mapping of the national basic map; completed the measurement of the geographic location and elevation of Mount Everest and the Antarctic Great Wall Station; carried out a lot of surveying and mapping work in conjunction with the national economic construction, such as the Nanjing Yangtze River Bridge, Baoshan Iron and Steel Plant, Beijing Positron Electronics Accurate stakeout and equipment installation measurements for projects such as colliders. In the manufacturing of surveying and mapping instruments, it has grown from scratch, and now it can not only produce a series of optical surveying instruments but also successfully developed advanced instruments such as photoelectric rangefinders, satellite laser rangefinders, and analytical mappers for various ranges. In terms of training of surveying and mapping personnel, tens of thousands of surveying and mapping technicians of various types have been trained, which has greatly improved the level of China’s surveying and mapping technology.
Especially in recent years, China’s surveying and mapping technology has developed faster. For example, the GPS global positioning system has been widely used, and the national GPS land network is about to be completed; in terms of geographic information systems, China’s first practical map system has been built in the executive meeting room of the State Council. And put it into use: This shows that China’s current level of surveying and mapping technology, although compared with the international advanced level, there is still a certain gap, but as long as we are determined to be strong and work hard, we can quickly catch up with and exceed the international level of surveying and mapping technology.