4 ms·

Re the radio synchronized watches, it's annoying that most of them listen to things like WWV, which is geographically limited. The Seiko Astron is probably the

by rdl 13y ago

Re the radio synchronized watches, it's annoying that most of them listen to things like WWV, which is geographically limited. The Seiko Astron is probably the best alternative, since GPS sync works over the whole planet. Unfortunately, expensive. (http://www.seiko-astron.com/ http://www.seiko-astron.com/) There are a lot of digital GPS watches (Garmin, Suunto, etc.), but some of them (for some reason) don't sync the displayed watch time to GPS time.

jrockway 13y ago
Watches actually listen to WWVB, not WWV. (WWV is on HF, WWVB is on LF.) On a good propagation day, you can probably hear WWV around the world. If it wasn't for other countries broadcasting their time stations on the same frequency, that is. Ultimately, LF time synchronization is a good idea. It doesn't depend on additional ionospheric information to get an accurate time transfer, since signals do not travel through the ionosphere. HF signals take different routes at different times of day, and GPS time transfer requires an accurate site survey and accurate ionospheric delay constants.
m_mueller 13y ago
There's also these: http://www.ablogtowatch.com/citizen-satellite-eco-drive-watch-gets-time-from-space/ http://www.ablogtowatch.com/citizen-satellite-eco-drive-watc... Btw. I happen to know the guy who directed the ad. I just don't understand why Japanese watchmakers don't market their GPS watches more heavily and in a much lower price range. I feel that there is a huge market gap for well made $300-700 watches with GPS synched time. There's cheap quartz that aren't synched, there's the expensive Seikos and Citizen watches ($1000-$3000), there's mechanical Swiss watches you have to set up yourself ($500 to whatever you want to pay) and there's mechanical watches with perpetual calendar (start at $10k or so). As a result, Swiss watchmakers get most of world's earnings. Others just try to either emulate the Swiss or cheap Japanese quartzes from the past.
pokstad 13y ago
Casio is coming out with their first GPS/WWV hybrid watch: http://www.ablogtowatch.com/casio-g-shock-gpw1000-first-watch-combines-gps-atomic-clock-radio-time-syncing/ http://www.ablogtowatch.com/casio-g-shock-gpw1000-first-watc...

by rdl 13y ago

jrockway 13y ago

Watches actually listen to WWVB, not WWV. (WWV is on HF, WWVB is on LF.) On a good propagation day, you can probably hear WWV around the world. If it wasn't for other countries broadcasting their time stations on the same frequency, that is. Ultimately, LF time synchronization is a good idea. It doesn't depend on additional ionospheric information to get an accurate time transfer, since signals do not travel through the ionosphere. HF signals take different routes at different times of day, and GPS time transfer requires an accurate site survey and accurate ionospheric delay constants.

m_mueller 13y ago

There's also these: http://www.ablogtowatch.com/citizen-satellite-eco-drive-watch-gets-time-from-space/ http://www.ablogtowatch.com/citizen-satellite-eco-drive-watc... Btw. I happen to know the guy who directed the ad. I just don't understand why Japanese watchmakers don't market their GPS watches more heavily and in a much lower price range. I feel that there is a huge market gap for well made $300-700 watches with GPS synched time. There's cheap quartz that aren't synched, there's the expensive Seikos and Citizen watches ($1000-$3000), there's mechanical Swiss watches you have to set up yourself ($500 to whatever you want to pay) and there's mechanical watches with perpetual calendar (start at $10k or so). As a result, Swiss watchmakers get most of world's earnings. Others just try to either emulate the Swiss or cheap Japanese quartzes from the past.

pokstad 13y ago

Casio is coming out with their first GPS/WWV hybrid watch: http://www.ablogtowatch.com/casio-g-shock-gpw1000-first-watch-combines-gps-atomic-clock-radio-time-syncing/ http://www.ablogtowatch.com/casio-g-shock-gpw1000-first-watc...