How many GPS systems are there?

Related questions

1. Who killed Galileo Galilei?
2. Who owns the GPS system?
3. Is Galileo compatible with GPS?
4. How Galileo was killed?
5. Are GPS satellites in geosynchronous orbit?
6. Was Galileo imprisoned?
7. How long will GPS satellites last?
8. How many types of GPS are there?
9. Does Google Maps use Galileo?
10. Why is Galileo Galilei so important?

Tags

1. #systems
2. #navic
3. #system
4. #satellite
5. #positioning
6. #there
7. #beidou
8. #china
9. #irnss
10. #india
11. #global
12. #japan
13. #navigation
14. #regional
15. #galileo
16. #additionally
17. #glonass
18. #russia