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: Weems Star Altitude Curves
    From: Murray Peake
    Date: 2020 Feb 8, 00:52 -0800

    Hi Tony,

    That's correct - the effect is more pronounced at higher latitudes. The idea was to allow the navigator to plot the distance run and course directly on the altitude charts. The non-linear latitude spacing is clearer in the example for 1945, Latitude 50 to 60 North, that I posted in 2017.

    Example 2 in the 1940 edition (epoch 1945) is for an aircraft, speed 240 knots, course 60 degrees true, 3 min 30 sec between observations.

    The 1940 edition had LST in arc rather than time (for convenient use with the Air Almanac) at the foot of the page, and an explanation and examples for the Royal Air Force on the last page.

    Were the Weems Curves actually used by the RAF?  The copy I have has an insert page with a table of GHA Aries for 1962. The editions seem to have been published in 1928, 1938 and 1940 (for 1945). 

    Best Regards

    Murray

       
    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