Newest GPS satellite goes active – Spaceflight Now
The Global Positioning System: Global Positioning Tutorial
How Does GPS Work? | Time and Navigation
China's version of GPS now has more satellites than US original - Nikkei Asia
GPS satellite networks are easy targets for hackers
Brief History of GPS | The Aerospace Corporation
Global Positioning System > United States Space Force > Fact Sheets
Triangulation | National Geographic Society
What is GPS? | NASA
GPS Block IIF - Wikipedia
GPS error caused '12 hours of problems' for companies - BBC News
GPS.gov: Space Segment
How Does GPS Work? | NASA Space Place – NASA Science for Kids
GPS Provides the Reference for Precision Time & Frequency Products | EndRun Tech
Global Positioning System
Global Positioning System > United States Space Force > Fact Sheets
Satellite navigation - Wikipedia
Feb. 14, 1989: GPS Enters Orbit | WIRED
Who really discovered GPS? | BBC Science Focus Magazine
Globalstar's GPS Satellite Network Vulnerable To Hackers | Fortune
