On this day, 31 years ago, on October 31, 1994 (September 27, 1994, the Potala Palace measured an exact height of 115.703 meters. On October 31, 1994, Xinhua Agency reported: What is the exact height of the Potala Palace? There have been opinions for a long time. Recently, two professors from Wuhan Technical University of Surveying and Mapping obtained new answers through accurate on-site measurements. The Potala Palace was built in the 7th century AD. After successive expansions, it has formed a grand scale of 13 floors and more than 1000 rooms. Traditional sayings, including atlases and various materials, adopt an approximate figure for the height of the Potala Palace: 117 meters. How this figure came to be arrived at is not clear. On the occasion of the completion of the renovation of the Potala Palace in 1994, the Potala Palace Management Office invited Xiang Huchu and Liu Guohui, professors from Wuhan University of Surveying and Mapping Technology who came to Xizang, to conduct an accurate measurement of the Potala Palace. Among them, Professor Xiang Huchu once participated in the measurement work of my country's Antarctic Great Wall Station. This measurement of the Potala Palace uses GPS global satellite positioning technology. This technology is currently the most time-saving, labor-saving and high-precision measurement technology widely used in the world. When conducting on-site surveys of the Potala Palace, the highest point chosen by the surveyors was the golden dome of the Fifth Dalai Lama's Spirit Pagoda, and the lowest point was the national permanent horizontal measurement point at the foot of the Red Mountain of the Potala Palace. The measurement results show that the actual altitude of the Potala Palace is 3,756.507 meters, and its exact relative height is 115.703 meters. The two experts explained that there is a certain gap between the new height of the Potala Palace measured this time and the traditional 117 meters. It is not because changes in the earth's crust have lowered the Potala Palace, but mainly because previous measurements were not accurate enough.