NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Does anyone use a stopwatch on the handle?
From: Peter Monta
Date: 2014 Oct 22, 13:00 -0700
I guess accounting for UT1-UTC is the user's problem---I don't think NTP carries it as side information.
Cheers,
Peter
From: Peter Monta
Date: 2014 Oct 22, 13:00 -0700
I've been using the Emerald Timestamp iOS app for various purposes (not yet for sextant sights, though). When a button is pressed, the app saves a UTC(NTP) timestamp good to 0.1 second or so (limited more by "personal equation" than timescale accuracy, probably). A bracket could be arranged to hold the phone near the sextant handle, or, as Greg says, the phone could just be held freehand while the other hand holds the sextant.
http://www.emeraldsequoia.com/ts/index.html
If your blue-water craft has no satellite phone and thus no Internet connection, no problem: at least it has a chronometer, so hook that up to some low-cost computer platform like a Raspberry Pi, which will then serve NTP to the phone over wifi. DNS server configuration will allow NTP-ish hostnames like 0.pool.ntp.org to resolve to localhost. Okay, it's a little overkill, but it's better than a hack stopwatch. (Isn't it? :-) )http://www.emeraldsequoia.com/ts/index.html
Cheers,
Peter
