Timeline for If I travelled in time to 1979... would my smartphone's gps still work?
Current License: CC BY-SA 3.0
10 events
| when toggle format | what | by | license | comment | |
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| Feb 27, 2017 at 8:48 | comment | added | hobbs | @Holger yes, the P(Y) code is still encrypted using keys that aren't publicly available. Reasons for this include the ability to deny GPS to civilians on short notice without affecting the military (although it would make various organizations including the FAA very angry), and the fact that the encryption hinders jamming (jamming civilian GPS is, apart from the fact that it's highly illegal, rather easy.) | |
| Sep 10, 2016 at 20:31 | comment | added | Dave Cousineau | as far as I recall, the US keeps available an emergency option to reduce the accuracy of GPS down to unusable levels at any time. | |
| Sep 9, 2016 at 15:53 | comment | added | Edheldil | @Holger the GPS still uses two frequencies, for military and for public use. The military signal is encrypted (which could, presumably, also ensure authenticity), the public one is not. Military frequencies are less susceptible to atmospheric noise than the public ones. | |
| Sep 9, 2016 at 13:27 | comment | added | KRyan | @Holger “no reason to keep them secret” just isn’t how classification schemes work; rather, they require a reason to make them public (or, more accurately, a reason for someone with the proper authority to devote the time investigating everything to make sure they’re safe to make public). The US currently has an enormous backlog of “really no reason that this should be secret but hasn’t been declassified yet” material, though admittedly most of it comes from the two wars that began in 2001 so if the code was declassified before that there may be a chance. | |
| Sep 9, 2016 at 13:08 | comment | added | Holger | When you say “Any device could listen to the signals, but only those with the proper codes could use them effectively”, it obviously raises the question whether these codes are still a secret. Since selective availability is history, there is no reason to keep them secret. But the bigger question is whether the modern receiver will work at all. | |
| Sep 9, 2016 at 12:59 | comment | added | Brian Risk | This answer seems to be addressing if GPS would work well. It seems the OP is asking if it would receive and interpret any signal at all regardless of accuracy. | |
| Sep 8, 2016 at 12:45 | comment | added | Skye | I love it when my IPhone GPS places me in the center of Pacific Ocean. | |
| Sep 8, 2016 at 11:01 | comment | added | OrangeDog | You know the McGuffin in Tomorrow Never Dies? You'd probably need one of those. | |
| Sep 7, 2016 at 21:20 | comment | added | supercat | Even with SA one could get much better accuracy if one had a live link to a GPS receiver at a known nearby location, since the same errors would be received by the receiver at the fixed location as by the unit of interest. When I was working with such systems in 1994, the equipment could have accurate GPS while one was willing to pay the per-minute cost of a cell modem connection. | |
| Sep 7, 2016 at 17:41 | history | answered | cobaltduck | CC BY-SA 3.0 |