What is the meaning of selective availability in GPS?

Related questions

1. What frequency does GPS use?
2. What was selective availability and why was it discontinued?
3. What is GNSS survey?
4. What is an intermediate fix?
5. How accurate is GPS in Australia?
6. What is an RNAV route?
7. What is anti spoofing in GPS?
8. When was GPS selective availability off?

Tags

1. #around
2. #selective
3. #position
4. #means
5. #masked
6. #receiver
7. #orbit
8. #signals
9. #earth
10. #availability
11. #describe
12. #because
13. #accurate
14. #accuracy
15. #satellites
16. #gives