Welcome to the NavList Message Boards.


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

Compose Your Message

Add Images & Files
    Fwd: Re: Sextant accuracy with short distance to horizon
    From: Dale Tilson
    Date: 2001 Jun 26, 1:50 PM

    Re: the Aussie using his fence for a horizon, several people wrote:
    > >> That's interesting. But surely one must make an allowance for the fact
    > >> that the fence is not at the same altitude as the horizon.
    > >
    > >I can't remember that much about the post, but I THINK he had some kind
    > of HE
    > >correction for his eye above the fence line.
    > >
    >He would need extremely accurate survey data if there was
    >any meaning to be had. He would have to know the relative
    >height of the fence and his eye, as well as the distance to
    >the fence.
    OK, guys, I'm new at this so somebody help me out.
    I thought the "dip" correction was necessary because the horizon isn't
    level with your height of eye.  Aren't we actually trying to measure
    altitude above a line horizontal with the line-of-sight?  If so, our Aussie
    friend would only need to find a perch so that his eye was level with the
    If not, somebody straighten me out quick, because I was gonna set up an
    observation post in the back yard based on that premise.

    Browse Files

    Drop Files


    What is NavList?

    Join NavList

    (please, no nicknames or handles)
    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 Settings

    Posting Code:

    Custom Index

    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