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: Intercept Method or Marcq St. Hilaire
    From: David C
    Date: 2020 May 14, 01:35 -0700

    Steve wrote

    It would appear that while the USPS method reduces the sight by the Law of Cosines, while the Hilaire method uses Haversines. 

    Are there other difference

    You are confusing two different things - the method used to plot a line of position (LOP) and the method used to reduce the sight.

    Marq St Hilaire devised the intercept method in which an intercept and an azimuth are used to locate a LOP. 

    There are various ways of reducing the sight. The Law of Cosines is one and the haversine formula another. Note that the haversine formula was devised decades after St Hilaire did his work. The sights can also be reduced with what are called short tables (such as HO28 Dreisonstok) and lookup tables (such as 24 & 229).

       
    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