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: Rude star finder
    From: Frank Reed
    Date: 2015 Dec 20, 13:03 -0800

    I hope to get to a longer, more general reply on this topic later today, but for now I have to comment on this one. Gary LaPook wrote:
    "although mine does more, it calculates the time of twilight and is automatically set for that time"

    This is a great function, which, I should say, a number of folks have independently invented, and it's something that a navigator's star finder should have had right from the beginning. The single most reasonable use for a star finder is setting up for evening twilight. And this can be done entirely by a turn of the wheel if the base plate includes a labeled ecliptic and if the altitude-azimuth overlays include arcs for an altitude of -12° (or some reasonable point for nautical twilight). All the navigator should have to do is rotate the overlay (for the nearest latitude, of course) until the twilight altitude arc crosses the correct date on the ecliptic. And that's it! Immediately read off the altitudes and azimuths of the stars. No calculation and no almanac required.

    The big issue with the standard Rude/H.O. 2102 star finder design is, quite simply, that it is a bad design. It's poorly done, and it's rather intricate to use. The design takes everything from a common planisphere ...and screws it all up. 

    Frank Reed

       
    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