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
    Quicker Ex-Meridian Formula for Slide Rule or Calculator
    From: Greg Rudzinski
    Date: 2016 Nov 29, 11:08 -0800

    This modified ex-meridian formula saved a few slide rule moves on the K&E (solution time 50 seconds).

    Slide Rule:

    a = (Cos Lat. Cos Dec.) / Sin (Lat. +/- Dec.)       (+) contrary name  (-) same name  *

    +XM' = .524 (a)(t)(t)       t = meridian angle in degrees and tenths  **

    Calculator:

    +XM' = (a)(t)(t) / 1.91

    notes: * The (a) value can be worked up prior to observation. ** Slide rule tip - pencil mark the slide C scale at .524 for quick cursor set.

                  +XM' = ex-meridian minutes of arc to be added to Ho then solve as a LAN observation.

    Greg Rudzinski

       
    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