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: Figuring Course given Lat/Long of destination
    From: Roger M. Derby
    Date: 2000 Feb 27, 7:24 PM

    Note that for great circle sailing, you only compute your "departure heading". 
     The heading you sail changes continuously (or as often as you refigure it.)
    
    Roger
      ----- Original Message -----
      From- Luis Soltero
      To: NAVIGATION-L{at}LISTSERV.WEBKAHUNA.COM
      Sent: Sunday, February 27, 2000 8:42 PM
      Subject: Re: Figuring Course given Lat/Long of destination
    
    
      There are several ways to solve this problem.  3 come to mind
      a) Using plane sailing formulations which are very inaccurate due
      to reasons you mention below.
      b) rhumbline computations using meridionals which compute
      distances based on Mercator projections.
      c) great circle sailing which will compute the shortest distance
      between both points very accurately.
    
      Alton B. Moody in navigation afloat also discusses something called mid latitude sailings
      which if memory serves me right uses the mean of the two given longs
      in the calculation.
    
      Anyway, all these sailings are discussed in great detail with formulas and examples in
      Bowditch.
    
      Cheers,
    
      --luis
    
        ----- Original Message -----
        From- Ed Kitchin
        To: NAVIGATION-L{at}LISTSERV.WEBKAHUNA.COM
        Sent: Sunday, February 27, 2000 5:49 PM
        Subject: Figuring Course given Lat/Long of destination
    
    
        An interesting problem appears in the latest issue of "Ocean Navigator" 
    Which asks that you figure the course to a destination given origination and 
    destination. It would seem easy to determine the difference in lat. (The 
    destination was over several degrees of lat.), but deg. of long. differ in 
    length as you change lat. One could simply take the mean of the two given 
    long. and use that, but that bothers me as not being all that accurate. There 
    is the error of the Macerator thing. You could use universal plotting sheets 
    and construct using a vertical representing diff./lat., then draw a 
    horizontal from the top of the lat. fig., representing the long. at the 
    destination, and draw a hypotenuse as the course line. (???) Are there any 
    mathematicians out there to
         give me a good formula to learn for this task? Thank you.
    
        Ed Kitchin
    

       
    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