Hacker News new | ask | show | jobs
by JCM9 1040 days ago
GPS signals are much higher frequency and very low power and thus don’t work indoors. These HF time signals are way more powerful and can be detected inside buildings.
2 comments

> GPS signals are much higher frequency and very low power and thus don’t work indoors.

With a $20 antenna placed near the window, together with a modern receiver, it is easy to get nanosecond level of precision for GPS systems. Some receivers even have in-door precision specification.

GPS not only work indoors, in terms of timing, it works actually pretty well indoors.

Why would I need that for? nanosecond accuracy? GPS indoors?
e.g. to get yourself a stable frequency standard that can be used in all kinds of electronics projects & equipments.
In the interest of the previous reply, Casio's GBD-H1000 has the ability to time sync with GPS.
Yeah but it needs to be charged often. That would be a compelling use case for the radio based timing synchronization that are in less power hungry watches, and I'm curious, if this watch just had GPS for timing and none of the other features, if it's power would last as long or even half as long as the older models.
The H1000 is marketed as a fitness watch and solar powered too. The GPS time sync is not an exclusive feature and I find that it isn't necessary to have it on constantly.