The entire world has come to depend on satellite navigation systems in the forty or so years since the first Global Positioning System satellites took to orbit. Modern economies have been built on the presumption that people and assets can be located to within a meter or better anywhere on, above, or even slightly under the surface of the planet. For years, GPS was the only way to do that, but billions have been sunk into fielding other global navigation systems, achieving a measure of independence from GPS and to putting in place some badly needed redundancy in case of outages, like that suffered by the European Union’s Galileo system recently.
The problem with Galileo, the high-accuracy public access location system that’s optimized for higher latitudes, seems to be resolved as of this writing. The EU has been tight-lipped about the outage, however, leaving investigation into its root cause to a few clever hackers armed with SDRs and comprehensive knowledge of exactly how a constellation of satellites can use the principles of both general and special relativity to point you to your nearest Starbucks.