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: A fluke of 0.0 intercept with Altair.
    From: George Huxtable
    Date: 2010 Sep 22, 08:42 +0100

    Antoine wrote-
    ...if we use tenths of arc minutes instead of arc seconds - which has 
    nowadays become most usual navigational practice -, we could as well use 
    the Civilian Aviation Format (this the one I am using to enter coordinates 
    in our Honeywell Flight Management Computers) through entering such 
    coordinantes as : N3013.2W08152.3
    Such format is quite compact. It also eliminates the use of ' (arc minute 
    symbol) which I sometimes cannot get to show up correctly in the NavList 
    Forum posts. It can also be easily extended if more significant figures are 
    required : N30�13'13" W081�52'16" will then show up as N3013.217W08152.267
    If using this specific aviation code, the height quoted by Paul would then 
    have been 4026.2 (or 40�26'2 in its classical transcription) while using 
    the 40.262 figure would imply decimal degrees (which was you initial and 
    early guess).
    This is just a suggestion and an idea in the air ... What do you think, my 
    Fellow Maritime Navigators about such an aviation format ?
    Response from George-
    HORRIBLE! A recipe for misunderstanding and disaster! May be OK for 
    entering data into a very specific instrument, but not in general 
    discussion in a forum such as ours, in which all sorts of quantities may 
    appear. Decimal numbers should mean decimal numbers, without a hidden 
    sexagesimal intrusion into them, which would take us back into the confused 
    number-world of the ancient Greeks and the Babylonians.
    Presumably, Antoine's format requires 4 digits before the decimal point, 
    for latitudes (up to 90º), and 5 digits for longitudes (up to 180º). What 
    about sextant angles, then? Would altitudes (never more than 90º) be 
    allocated 4 digits? In which case, lunar distances (up to 120º) would 
    require 5.
    If a contributor can't find acceptable symbols for degrees and minutes, he 
    can always use the appropriate letters, d, m, s. Where's the problem?
    contact George Huxtable, at  george{at}hux.me.uk
    or at +44 1865 820222 (from UK, 01865 820222)
    or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. 

    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