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
    Longhand Sight Reduction
    From: Greg Rudzinski
    Date: 2014 Jun 9, 09:08 -0700

    The attached index card shows a sight reduction done longhand to 4 places using cosine and haversine tables. This is a manageable method for those who want to avoid logs. The beauty of the haversine table as presented in Bowditch is that LHA can be directly entered and formula rules are simple. 

    hav z = hav(L~d) + cosL cosd havLHA

    Hc = 90 - z  

    L-d same name

    L+d contrary name

    A compact set of cosine haversine tables, Ix diagram, and LTA would make a nice sextant box booklet. The question now is can a 10" sliderule sight reduction do a better job if scaled with haversines ?

    Greg Rudzinski

     



    File:



       
    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