News for hackers. Stuff that matters.

A comment on 60 kHz (2022). Parent comment

Re:60 kHz (2022) by morpheuskafka on Friday May 31, 2024 @11:34PM (#40542668)
> a more popular idea seem to be to piggy back onto GNSS signals

Don’t all GNSS systems provide a highly accurate time signal (maybe needed for computing the distance to satellite)? I know GPS does at least.

[ Parent | on HN ]
Re:60 kHz (2022) by lxgr on Friday May 31, 2024 @11:56PM (#40542752)
Yes, the GPS signal in a way is primarily a very precise time signal :) It’s a TDOA system!

I was referring to piggying back an emergency signal onto that!

[ Parent | on HN ]
Re:60 kHz (2022) by BenjiWiebe on Friday May 31, 2024 @11:53PM (#40542740)
Yes, it is needed to compute a location. More accurate time = more accurate location.
[ Parent | on HN ]
Re:60 kHz (2022) by stkdump on Saturday June 01, 2024 @12:37AM (#40542912)
As mentioned somewhere else, these time signals also carry information about DST and adapt for leap seconds, both of which GPS doesn't do as far as I know. I remember that earlier versions of Android always set the phone clock to GPS which was then off by a number of seconds.
[ Parent | on HN ]
Re:60 kHz (2022) by kqbx on Saturday June 01, 2024 @05:29AM (#40544197)
GPS navigation messages do include information about leap seconds and other stuff necessary to convert between GPS time and UTC. See GPS Interface Specification IS-GPS-200, 30.3.3.6.2 - UTC and GPS Time
[ Parent | on HN ]