Canopus
Pseudo-Satellite Navigation System
Work principles
GPS principle
GPS determines a receiver’s location by using trilateration—calculating the distance to at least four orbiting satellites based on the time it takes for their unique radio signals to arrive.
Key information in pseudo-range equations
That is the whole trick.
A cellphone is set in the future time
Positioning, Navigation, and Timing (PNT) failure where GPS signal jamming prevents location fixes while the unsynchronized future time setting on the phone corrupts all remaining time-dependent system operations.