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
    Name or NavList Code:
    Email:
       
    Reply
    Re: Where are you most likely to be in the triangle?
    From: Frank Reed
    Date: 2017 Jan 21, 20:20 -0800

    Stan K, you asked:
    "Which one of these, if any, corresponds to the point that Herbert Prinz discussed at a Mystic Seaport Navigation Weekend a bunch of years ago?"

    Yes, that was the "symmedian point" which HP discussed in his presentation at the Navigation Weekend in 2008. We should have another one of those gatherings soon. Maybe in June? Or October? How about New Bedford for a change of scene? I know a great venue where I am confident we could meet.

    Herbert Prinz in his presentation demonstrated the ruler and compass construction which Bill Lionheart described in his post. That's certainly interesting and neat to see once. But in practical navigation, it's probably over-kill. Personally, I think the most important aspect of this for a navigator is to know how to deal with a long, skinny triangle -- the fix goes near the short side. The rest of it is too narrowly focused on three sights. A navigator should see a good sampling of computer simulations of fixes and error ellipses derived from 3, 4, and 5 and more sights. With a little familiarity, enough patterns emerge so that the navigator can make a rational choice in a real world case. The lessons from that kind of "neural network" training should include realizing that the fix is near the short side (as I just mentioned) and also that the error ellipse is usually larger than the triangle (as Bill B mentioned) and that the error ellipse gets smaller while the "tangle" of plotted lines of position grows larger with a larger number of sights (more sights may look worse in the plot, but it's actually more accurate). We can and should train instinct on this sort of thing.

    Frank Reed
    ReedNavigation.com
    Conanicut Island, New England

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Get a NavList ID Code

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

    A NavList ID Code guarantees your identity in NavList posts and allows faster posting of messages.

    Retrieve a NavList ID Code

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

    Email Settings

    NavList ID 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