Comparing GPS and Galileo can expose a position discrepancy if one system is being spoofed. Multiple receivers provide another comparison: a failed receiver need not remove every source of position information. Crews can use the balance of readings to recognize that something is wrong. The discussion also names Russia's GLONASS and China's BeiDou as other satellite-navigation systems. GPS's relative reliability is presented as an assessment, while a possible future commercial system remains speculative.
Notable Point · 4:23:02-4:24:20
Why ships benefit from GPS and Galileo together
Separate satellite constellations and multiple receivers give ships position readings to compare when a signal is spoofed or equipment fails.