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: Azimuth Formula Questions
    From: Paul Hirose
    Date: 2005 Oct 31, 11:59 -0800

    George Huxtable wrote:
    > But now let the observer travel a few feet South, across the equator, to a
    > lat of -.001 degrees South.
    >
    > Plugging in that new value of lat changes Z to 44.967, almost exactly the
    > same as before (jst as we would expect, for such a small movement of the
    > observer).
    
    That's not what I would expect. Isn't Z measured from the pole nearest
    the observer? At least, that's how HO 229 defines it. Stepping into the
    Southern Hemisphere changes the scenario to "latitude CONTRARY name to
    declination". That means you must use a different HO 229 page (the
    facing page in the same book opening) to obtain Z. The tabulated value
    is 135.0 for your example. Then apply the correct rule
    
    >> S. Lat
    >> L.H.A. greater 180..........Zn = 180-Z
    >> L.H.A. less than 180........Zn = 180+Z
    
    and all is well.
    
    However, I never used the rules, preferring to plot directly from Z. In
    your example, Z = S 135 W. On paper I find that as easy to plot as 315,
    and it eliminates the Zn calculation.
    
    
    

       
    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