Several important concepts of satellite positioning

1. The full name of GNSS is the Global Navigation Satellite (Navigation satellite System), which refers to all satellite navigation systems, including global, regional and enhanced, such as the U.S. GPS, Russian GLONASS, and European Galileo , China's Beidou satellite navigation system, as well as related enhancement systems, such as the United States Waas (Wide area Enhancement system), Europe's EGNOS (European static navigation overlap system) and Japan's MSAs (multi-purpose Transport satellite enhancement system), but also covers the construction and future development of other satellite navigation systems.

2, NMEA is the United States National Oceanic Electronics Association abbreviation, is the GPS navigation Equipment Unified RTCM Standard protocol.

The data format of the Beidou protocol and the NMEA Protocol is identical, the only difference between the two protocols is that the protocol header is different, such as :

NMEA Agreement : "Gpgga",

The corresponding Beidou protocol is "Bdgga"

In addition, Gngga said GPs and Beidou hybrid positioning, such as the positioning of the satellite a total of 7, of which 5 are GPS positioning, 2 is the Beidou positioning

3, AGPS, auxiliary global satellite positioning system, is a kind of GPS operation mode. It can use the mobile phone base station information, with the traditional GPS satellite, so that positioning faster.

Several important concepts of satellite positioning