Brief Introduction to the Four Major Satellite Navigation Systems

[SawyerDella]

Here is an introduction to the four major satellite navigation systems: 1. United States: GPS System: The GPS system was developed by the U.S. government in the 1970s and was fully completed in 1994. Currently, the U.S. GPS satellite positioning system is fully operational, with a total of 31 satellites in orbit, covering 98% of the Earth's surface. The GPS system provides navigation and time calibration services to 95% of users worldwide. 2. India: IRNSS System: The Indian Regional Navigation Satellite System (IRNSS) consists of 7 satellites and is expected to be operational by 2014. Currently, the IRNSS is in the debugging phase. 3. European Union: Galileo System: The Galileo system will officially become operational in 2014. Once in service, it will provide highly accurate positioning and navigation services with a precision of 1 meter for road, rail, air, and maritime transport within EU member states, as well as for hikers. Currently, only one of the two test satellites in the Galileo system is operational. 4. China: BeiDou System In December 2011, China launched the BeiDou/Compass system as a pilot project. According to Ran Chengqi, Director of the China Satellite Navigation System Office, BeiDou can currently provide navigation and positioning services for China and its neighboring countries. Ran Chengqi stated: "China's system can not only display the accurate location of users but also determine the time, and users can send text messages." Currently, the 10 satellites of the BeiDou navigation system cover an area from Australia in the south to Russia in the north, and from China's Xinjiang Uygur Autonomous Region in the west to the Pacific region in the east. In 2013, China plans to launch 6 more satellites to expand coverage, and by 2020, the system will have a total of 35 satellites. Currently, the BeiDou navigation system has an accuracy within 25 meters, which will improve to 10 meters next year. The BeiDou system will contribute to the development of China's navigation industry.

[VanRose]

I usually pay a lot of attention to navigation when driving. The four major satellite navigation systems are essentially the American GPS, Russia's GLONASS, China's BeiDou, and the EU's Galileo. GPS is probably the earliest, and it's still the main system used for mobile navigation today—it's really fast at positioning. BeiDou is our own Chinese system, and it has made rapid progress over the past decade or so. Not only is its navigation accurate, but it can also send text messages for help, which is super convenient. GLONASS is mainly used in Russia and surrounding areas, and I've heard it has good anti-jamming capabilities. Galileo is developed by Europeans and has high positioning accuracy, but I personally don't use it much. Nowadays, higher-end dash cams can receive signals from multiple systems simultaneously, making positioning even more reliable.

[FinleyMarie]

For frequent self-drivers, the choice of navigation system is quite important. There are four mainstream global systems: the American GPS is a veteran player with wide signal coverage, relied upon by most car navigation systems; Russia's GLONASS performs better in extremely cold regions; China's BeiDou is now truly widespread, offering not only precise positioning but also two-way communication, making it ideal for off-road driving; Europe's Galileo boasts high positioning accuracy but lacks popularity. Nowadays, many new cars use multi-mode chips, switching between the four systems to avoid signal loss. I still remember the scare when my navigation froze in a tunnel—now I always check if a car supports multi-system switching before choosing. Safety comes first, after all.

[Cayden]

I work in logistics and transportation, using navigation systems every day. Currently, there are only four operational navigation systems globally: the American GPS, which has near-global coverage but tends to drift when used alone; Russia's GLONASS, which performs well at high latitudes; China's BeiDou, which has made significant progress in recent years with its sub-meter level accuracy, making it particularly useful for our deliveries; and Europe's Galileo, which was completed not long ago. Many trucks now come equipped with multi-mode navigation modules, allowing drivers to switch between systems during long-haul trips. For example, when entering mountainous areas, we use BeiDou and GPS together for double reliability—the signal becomes much more stable, eliminating the issue of taking wrong routes and delaying deliveries.