Global navigation satellite systems

Assembled from 25 blocks · 3 evidence · 24 related

1. Story
2. The collective name for the satellite constellations that broadcast position and time: the American GPS, the Russian GLONASS, the European Galileo and the Chinese BeiDou, together with regional augmentations such as Japan's QZSS and India's NavIC. Each works the same way — a receiver measures the arrival time of signals from four or more satellites carrying atomic clocks, and solves simultaneously for three position coordinates and its own clock error. Economically it is the strangest large business in space, because it is not a business. The constellations are built, launched and operated by states at public expense and the civil signal is free at the point of use, with no metering, no subscription and no contract between the operator and the user. All measured revenue is therefore downstream: receiver chipsets, devices, augmentation services and applications. On the industry's own accounting that downstream figure runs to hundreds of billions of euros a year, which makes GNSS simultaneously the most economically consequential space system in existence and one that appears on no operator's income statement. Not a place — the constellations occupy medium Earth orbit.
3. Knowledge
4. Orbital shells as distinct economic regimes
5. Global navigation satellite systems
6. Connections
7. Upstream and downstream in space accounting
8. Orbital shells as distinct economic regimes
9. GPS (Navstar Global Positioning System)
10. Galileo
11. BeiDou Navigation Satellite System
12. GNSS timing dependency
13. The first Navstar GPS satellite launches
14. GPS reaches full operational capability
15. Selective Availability is switched off
16. Galileo declares initial services
17. BeiDou-3 completes deployment and enters global service
18. Global navigation satellite systems
19. Low Earth orbit broadband constellations
20. Intelsat I (Early Bird) becomes the first commercial geostationary satellite
21. OneWeb completes its first-generation constellation
22. Evidence
23. Supports the finding that GNSS downstream revenue — devices, chipsets and services — runs to hundreds of billions of euros a year while Earth observation data and services revenue is smaller by roughly two orders of magnitude. V55 verification basis: not retrieved in this session; the contrast in magnitude is stated, the current-edition figures are not.
24. Supports the GPS milestone dates (first Block I launch 1978, full operational capability 1995, Selective Availability discontinued 2000) and the standing policy that the civil GPS signal is provided worldwide free of direct user charge. V55 verification basis: gps.gov was not retrievable in this session; dates are stated from author knowledge and require confirmation.
25. Estimates the economic cost to the United Kingdom of a multi-day national GNSS outage, and enumerates the infrastructure sectors dependent on GNSS timing. V55 verification basis: the report was not retrieved in this session, so the headline figure is described only as several billions of pounds over five days rather than quoted.