Shaanxi: More Beidou navigation base stations will be built to greatly improve Beidou system accuracy
Recently, a reporter interviewed the front-line mapping team members in Shaanxi and witnessed their true wild life.
When the reporter came to the hinterland of the Qinling, the leveling surveying team of the First Surveying and Mapping Engineering Institute of Shaanxi Province where Xing Xiongwang belonged had been working almost for the whole morning. With a leveling instrument and two scale plates, Xing Xiongwang stopped and went and repeated the same actions—placing the leveling instrument, aiming ruler, reading and recording the number.
Leveling is a method of measuring the height difference between two points on ground using leveling instruments and leveling rods. Specifically, the method is to set the leveling instrument between two points on ground and then observe the leveling scale erected on the two points. The height difference between the two points can be calculated the according to the number on the rod. Usually the elevation of each point is measured station by station along the selected leveling route with the starting point at the leveling origin or any known elevation point. As a precise measuring method, leveling is mainly used to establish an elevation controlling network in a country or region.
Xing’s team was conducting a second-class level measurement for the construction of Beidou satellite navigation and positioning base station system. On this relatively flat road, they measured every tens of meters. When they encountered a steep slope, they could only compress the sight line, sometimes even to two meters. In addition, leveling is also affected by factors such as light. “As the sun goes by at noon, the water vapor on the ground will evaporate. At this time, the phenomenon of “refraction” will occur and affect the reading. Therefore, in order to ensure the accuracy of the data, we often have to race against time.” said Xing.
Although it was a second-class level measurement, the accuracy requirement was still very strict. If there were more than 20 measurement points on a leveling line, accidental error per kilometer must be calculated and the accidental error per kilometer cannot exceed 1 mm. Accuracy is the basic requirement for surveying and mapping operations and is also what every surveyor pursues. Whether it is field operations or indoor analysis, they take the accuracy of images and data more seriously than anything.
Despite the hard work, Xing Xiongwang was very proud when talking about Beidou navigation base station under construction: “with more base stations, the precision of the Beidou system will be greatly enhanced.” It is learned that after the project is fully completed, the “space-earth integrated” Beidou system will provide real-time spatial position reference, satellite navigation and positioning services with high efficiency and precision for Shaanxi and neighboring provinces. By then, Beidou’s high-precision positioning will be as convenient as water and electricity for residents, a on-demand public service within your easy reach that benefits millions of households and all walks of life.