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
    Averaging lunars: was Lunars with SNO-T
    From: Alexandre Eremenko
    Date: 2004 Oct 30, 15:40 -0500

    Der George,
    Your message of Fri Oct 29 2004 - 13:21:42 EDT
    and your previous message on the subject
    seem to challenge me (and other interested participants)
    to start a little research project on
    "Non-linearity and averaging in Lunar distances".
    I agree with you that my "second lunar observation series"
    posted here was probably on the boundary of what should
    be permitted to average. It could be even "beyond this boundary",
    and I was just lucky to obtain improved results by the averaging.
    (Well, this is the part of my common sense philosophy:
    Averaging USUALLY improves the results. If your COMMON SENSE
    says "do average" then DO. I don't want this to be challenged
    to extort "quantitative statements":-)
    I just cannot make them.
    The sole purpose of my
    "balcony navigation" is to get some experience. That's why I
    reduce all results, then average and reduce the average results,
    then compare... After many trilas like that, I will deduce
    some EXPERIENCE, for example, under what circumstances averaging
    helps, and when it is dangerous. (So far,
    all my experience show that it helps). Then (I hope) I will have
    some experience in Sea in "small craft" conditions and maybe
    in "large craft conditions" as well:-)
    But of course, one can try to make a complete mathematical
    theory of "non-linearity in Lunars", similar to what I tried
    to do in "non-linearity of Altitudes".
    What makes me reluctant to start such attempts is
    a) I somewhat distrust "theories" when applied to the real world,
    in any case, it is only repeated EXPERIMENTS can can convince us
    that such-and-such theory is really applicable.
    And I believe other people on this list feel the same.
    b) Herbert Prinz (who apparently knows what he says, and
    apparently has some experience) in
    his message which triggered this whole "Averaging" discussion
    said that "Averaging is OK for Lunars".
    c) He (Herbert Prinz), in the same message, also gave references
    to the literature where this question of Averaging and
    non-linearity was thoroughly
    It is true, I could never find his reply on my message asking
    for PRECISE references, but I think it is only because of my poor
    copmmand of the search engine on this list.
    So, if this question was carefully investigated, and
    the results were published, why don't wee
    just look at these papers instead of inventing a bicycle again?

    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