Welcome to the NavList Message Boards.

NavList:

A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
       
    Reply
    Re: Does anyone use a stopwatch on the handle?
    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?  :-) )

    I guess accounting for UT1-UTC is the user's problem---I don't think NTP carries it as side information.

    Cheers,
    Peter

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Join NavList

    Name:
    (please, no nicknames or handles)
    Email:
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.
    Email:

    Email Settings

    Posting Code:

    Custom Index

    Subject:
    Author:
    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site