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
    Re: Lunar distances
    From: Steven Wepster
    Date: 2002 Jan 29, 3:53 AM

    Dear List,
    I think that the article cited by Trevor is not really suitable as an
    introduction to lunars. It was written by the staff of HM Almanac Office on
    the occasion of two centuries of Nautical Almanacs. It presents an
    "objective assessment of the method of determining longitude by the
    measurement of lunar distances, in terms of modern knowledge, outlook,
    notation and computing facilities." [taken from introduction to the
    article]. There are appended tables of precomputed lunar distances for feb
    and aug of 1967 and an example calculation. The article also includes a
    discussion of verious other methods of longitude determination that you may
    find interesting.
    However, I have to stress that the lunar distances appended already include
    semidiameters. This simplifies the calculations a bit but it makes their
    method and computation harder to compare. It is different from the
    classical text-books.
    Steven Wepster                          wepster{at}math.uu.nl
                                            tel +31 30 253 1186
    Mathematisch Instituut
    Universiteit Utrecht
    PO Box 80.010
    3508 TA Utrecht
    The Netherlands
    >There is also the paper "A Modern View of Lunar Distances" published in
    >the Journal of the Institute of Navigation in 1966. (It is pages 131 to
    >153 of volume 19). I copied it years ago but have never read it.
    >However, I can confirm that it includes a technical explanation
    >(peppered with equations), sufficient tables to allow for the clearing
    >of lunar distances with the data from the Nautical Almanac of the late
    >1960s (which for all I know may have had data missing from more recent
    >editions), and a worked example.
    >Trevor Kenchington
    >Trevor J. Kenchington PhD                         Gadus{at}iStar.ca
    >Gadus Associates,                                 Office(902) 889-9250
    >R.R.#1, Musquodoboit Harbour,                     Fax   (902) 889-9251
    >Nova Scotia  B0J 2L0, CANADA                      Home  (902) 889-3555
    >                    Science Serving the Fisheries
    >                     http://home.istar.ca/~gadus

    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