New surveying technology recalibrates height of Mt. Qomolangma 8,848.86 meters
The new height of Mount Qomolangma, the world's highest peak, is 8,848.86 meters, according to a joint announcement made by China and Nepal on Tuesday.
The accurate height measurement of the world's "top" serves to symbolize developments in China's surveying and mapping technology.
The latest elevation survey utilized a variety of technologies and equipment, including Global Navigation Satellite System (GNSS), radar and gravity measurement techniques, remote satellite sensing, and quasigeoid refinement, among other means, with many of the core devices independently developed by China. The gravity measurement used for the mission to calibrate the world's highest peak is the first of its kind.
Compared with the measurement in 2005 where GPS was the pillar for the satellite computation, this year's survey relied on Beidou from China, GPS from the U.S., GLONASS from Russia, and Galileo from the European Union, with the Beidou data being the main reference.
Chinese and Nepali surveyors reached the summit of Mount Qomolangma on May 27 and May 2019 of this year, respectively, to conduct measurements. However, these measurements only helped obtain first-hand data rather than the exact elevation of the mountain, for subsequent data processing is another big challenge.
"With the high altitude, extreme cold, and oxygen deficit on Mount Qomolangma — as well as it being home to some of the most violent crustal movements in the world — it's extremely difficult, challenging, and complicated to gain an accurate elevation reading," commented Guo Chunxi, director of the Geodetic Data Processing Center of the Ministry of Natural Resources. This is the third time that Guo has participated in the task of calculating the height of the mountain.
One difficulty in the latest data processing work lies in the significant amount of data to sift through. "Data is collected from the base stations every second, including information from more than 50 navigation satellites," Guo explained.
Given the complexity of the data processing, preparation for the reading began as early as last year, which involved formulating a processing scheme, building data models, and testing programming software, according to Guo.
Guo added that the latest measurement was markedly more scientific, reliable, and innovative than the previous attempt in 2005 thanks to the application of multiple homegrown technologies.
Sun Heping, an academician from the Chinese Academy of Sciences, analyzed that the precision of this calculation is the highest ever thanks to the application of a gravity survey, which provided the most accurate base for the measurement.
The data obtained from this scientific exploration of Mount Qomolangma not only enables the accurate calculation of the peak's height but can also contribute to efforts for ecological environment protection, geological surveys, crustal movement monitoring, and topographic surveying and mapping, as well as infrastructure construction in the surrounding area.
In addition, this mission lays a solid foundation for the maintenance and updating of China's modern surveying and mapping systems and provides basic surveying and mapping support for the management of natural resources in the country.
（You can also read it at:http://www.china.org.cn/world/2020-12/11/content_77003370.htm）