Author: bellasales

The Beidou Satellite Navigation System is a satellite navigation system independently built and operated by China, providing high-precision positioning and navigation services for global users. The Beidou positioning satellite can provide high-precision positioning, navigation, and timing services, and is widely used in many fields such as transportation, surveying, and rescue. The Beidou positioning satellite achieves global coverage, precise positioning and navigation, and assists in intelligent travel, agricultural production, and disaster relief work.

The actual constellation PDOP value of the Beidou satellite navigation system has reached the international leading level. The indicator parameters of a navigation constellation mainly include the number of available satellites in orbit and the Position Dilution of Precision (PDOP). The number of available satellites determines the coverage of the constellation's navigation signal, while PDOP is an important indicator used to measure the positioning accuracy of satellite navigation systems and the geometric strength of observation values, usually determined by the standard single point positioning observation equation.

Beidou-3 is the world's first satellite navigation system to provide three frequency signal services. The use of dual frequency signals in satellite navigation systems can weaken the impact of ionospheric delay, while using triple frequency signals can construct more complex models to eliminate high-order errors in ionospheric delay and improve the efficiency of carrier phase ambiguity resolution. In theory, this can improve carrier convergence speed. Therefore, the subsequent GPS will also adopt a three frequency signal system.

The Beidou short message communication service is a unique and important feature. It enables BeiDou users to send and receive short message information through BeiDou satellites even in areas without ground communication network coverage