What is the principle of Beidou satellite positioning and navigation?

The principle of Beidou satellite positioning and navigation is that the distance measurement between the satellite and the user is based on the difference between the transmission time of the satellite signal and the time of arrival at the receiver, which is also called pseudo-range. In order to calculate the user's three-dimensional position and receiver clock deviation, pseudo-range measurement needs to receive signals from at least four satellites.

The concept of "time delay" (time delay) is implemented in satellite positioning: the time difference of arrival from satellite to receiver is obtained by using the precise position of each satellite and the navigation information generated by the on-board atomic clock sent continuously.

Because the position of the satellite is accurately known, we can get the distance from the satellite to the receiver in the observation of the satellite by the receiver. Using three-dimensional coordinates and the distance formula in three satellites, three equations can be formed to solve the position (x, y, z) of the observation point.

The time of the satellite navigation system is maintained by the cesium rubidium atomic frequency standard of the atomic clock on each satellite. Generally speaking, the accuracy of these stellar clocks is within a few nanoseconds of Universal Coordinated Time (UTC). UTC is maintained by the "master clock" of the US Naval Observatory, and the stability time of each master clock is several 10- 13 seconds.

Beidou navigation application of extended data

1. Beidou navigation makes agriculture smarter. In Xinghua National Grain Production Function Demonstration Zone, Jiangsu Province, a variety of unmanned agricultural machinery realized unmanned operation with Beidou satellite navigation system.

2. Relying on the Beidou satellite navigation system, the accurate position and historical trajectory of the target vehicle can be queried in real time, and the bus can be dynamically supervised.

3. Guangxi has established a complete geological monitoring system platform by using the new generation Beidou cloud automatic monitoring technology, which can quickly control the hidden dangers of disasters.

4. The demonstration application project of "Beidou+Smart Community" in Guangming Community, Pengjiaqiao Street, donghu district, Nanchang City, Jiangxi Province has important demonstration significance in providing accurate positioning, location call for help, location inquiry, public transportation, property management and other convenient services for the elderly in the community.

Baidu Encyclopedia-Beidou Satellite Navigation System