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: ZT vs LMT.
    From: Chuck Taylor
    Date: 2000 Dec 07, 1:21 AM

    Dave W wrote:
    
    > Is it appropriate to use Local Mean Time as being
    > synonymus with Zone Time?
    
    No.
    
    > My notion of LMT is the time when some event is
    > going to occur at the prime meridian.  The
    > presumption being that this event will then occur
    > at every other meridian.
    
    That is essentially true for specific cases, such as the time of
    meridian passage or the time of sunrise/sunset.
    
    >
    > or
    >
    > LMT corrected for longitude (ARC to time) yields
    > GMT.
    
    Yes.  Also, LMT corrected for the difference in longitude between
    your meridian and the zone meridian (even multiple of 15 degrees
    of longitude) yields ZT (and vice versa).
    
    >  GMT corrected for zone description (+ or -)
    > gives ZT.
    
    Yes.
    
    > If you take a test that says "At 1945 hours,
    > after passing Catalina Island and establishing an
    > evening star fix..."
    >
    > then
    >
    > The next statement reads "All times on this test
    > are either LMT or UT"
    >
    > What kind of time would you take 1945 hours to be?
    
    I would take it to mean ZT, irrespective of the next
    statement.  I think the person who wrote the test goofed.
    
    Usually the only time you care about LMT is when computing
    the time of meridian passage or the time of a solar event
    such as sunrise/sunset/twilight.
    
    Chuck Taylor
    Everett, WA, USA
    

       
    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