Detailed explanation of the core technology and features of GNSS receivers

GNSS receivers are a common type of instrument in engineering inspections. Their main function is to monitor the horizontal and vertical displacements of various structures. The fundamental reason why an instrument can monitor the displacement in two directions at the same time is that it uses GNSS positioning technology.

Let's briefly popularize what GNSS positioning technology is? When it comes to satellite positioning, we have to mention GPS. GPS is the global positioning system, which is a high-precision radio navigation positioning system based on air satellites. It is more used in the positioning sector of the automotive industry and logistics industry. GNSS refers to the global navigation WeChat system, which uses a group of satellite pseudoranges, ephemeris, satellite launch time and other observations. The purpose is also different from GPS. GNSS positioning can provide us with 24-hour uninterrupted three-dimensional coordinate positioning, speed and time monitoring values at any time at any location on the surface of the earth or in the near-Earth space area. And the accuracy is far above GPS. This is also the reason why GNSS is used in most engineering monitoring projects. There are two key parameters required for engineering monitoring. One is to provide monitoring data continuously and uninterruptedly, and the other is not affected by the location of the monitoring point. Any location must be able to monitor.

Taking advantage of the positioning technology of GNSS, various GNSS receivers have come into being. They are widely used in surveying and mapping, mechanical control, deformation monitoring, transportation, meteorology, scientific research and other fields. This article mainly introduces and analyzes the application of receivers in engineering monitoring. That is, geodetic GNSS receivers are mainly used for precision engineering measurement. The main principle is to use millimeter-level carrier phase observation values for relative positioning. It has high positioning accuracy, strong stability, and relatively complex instruments. The price of instruments on the market is relatively expensive.

GNSS receivers are mainly divided into four parts: upper cover, lower cover, protective ring and control panel.

GNSS receivers are generally not used alone, but need to be used in conjunction with a centering pole or tripod (with a base). When assembling, you need to assemble the various accessories of the receiver first, including battery installation and UHF radio antenna installation, and then combine the assembled receiver with the centering pole, tighten it through the connecting screw hole, and finally open the centering pole to a certain angle, level the centering pole, and then complete the assembly.

There are three functions of China GNSS receivers, which can also be called three working modes. The first working mode is static mode, the second is base station mode, and the third is rover mode.