GNSS system -GNSS is an abbreviation for Global Navigation Satellite System. For a long time, it has two names: global navigation satellite systems and global navigation satellite systems. Began in the mid-1990s, the European Union in order to break the American satellite positioning, navigation and timing monopoly position in the market, access to huge profits in the market, increase employment opportunities for Europeans, has been committed to an ambitious global civil navigation satellite system program, called the Global Navigation satellite system. The program implemented in two steps: The first step is to establish a US GPS system and Russia's GLONASS system, the first generation of global navigation satellite system utilization (then known as GNSS-1, which later built EGNOS); the second step the establishment of a fully independent from the US GPS system and Russia's GLONASS system, the second generation of global navigation satellite system, which is under construction in the Galileo satellite navigation system. Thus, GNSS from the advent of a, not a single sign system, but includes a GPS, GLONASS constellation, including a comprehensive system. In recent years, GPS receiver manufacturers have introduced high-performance GNSS receivers. As the PENTAX Smart 78/88, Smart 8800, the latter can be upgraded to 72 channels, the GNSS receiver becomes true sense.
GPS is currently the only - running to provide global coverage, all-weather, continuous, satellite navigation systems round the clock service capabilities, GLONASS due to insufficient number of satellites rather than have this ability. But such a situation in the future 5---10 years will be changed, because there are more systems added to GNSS "family." Galileo system is started in the EU and ESA joint initiative, Europeans own global satellite navigation system designed to get rid of dependence on GPS. "Compass II" is the next generation of satellite navigation system GPS-like. Although Galileo and "Compass II" has not yet run the network, but in the future they will become a strong contender for GPS and GLONASS. Of course, Americans do not want to see their GPS system is exceeded, then the GPS modernized. In fact, GPS modernization from the late 1990s began.
After GLONASS has experienced a long period of time, "quiet", with Russia's economic recovery, GLONASS system once again gained in importance. According to Russian official sources, the 2010--2011 years, GLONASS will have 24 satellites, then it will truly have global reach. GPS modernization is designed to add additional civil signals as well as to improve the accuracy of the system, while adding new, stronger anti-interference ability military signal. Civilian self-proclaimed Galileo in the early stage of development using the navigation field in recent years. New technologies and research aimed at increasing user selectively provide higher accuracy than GPS navigation and positioning, which is the Galileo system has been promoting one advantage. our country's. After the Compass II "and a GPS class. Like, in the development process are constantly using the new technology .GLONASS rebirth, the government has also announced that it will add a new navigation signal, changing the signal format, etc. can be seen from these trends navigation systems, future precision GNSS systems will continue to increase, selectable signal will also be more and more.
