Hacker News Reader

Well, they would, if they knew which epoch they were in, which isn't transmitted by the satellites, and on many receivers, isn't something an end user can easily change.

I have many fine examples of early to mid 1990s GPS receivers which can, eventually, get the full almanac and determine the geographical coordinates, but can't correctly figure out what day it is.

View on HN

> Well, they would, if they knew which epoch they were in, which isn't transmitted by the satellites

Realistically that is only a problem for devices not yet supporting the 13 bit week field or if we still use GPS in 150 years and even then heuristics could solve this problem unless devices exist that without software updates will live for longer than ~100 years.

Ah, yes. The infamous 1024-week (19.5 years) GPS epoch. I take back my "two decades" claim.

I think with some of my Garmin units you can connect them via serial and use an old Windows 98 application to sync the current PC time, which it will use as the basis for figuring out what week it's in. I haven't gotten the application working though.

Reply on news.ycombinator.com