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
    More on 2102-D & Radar Plotting Sheet
    From: Greg Rudzinski
    Date: 2010 Oct 12, 17:56 -0700

    This version of the 2102-D and radar plotting sheet (see linked images) has GHA of Aries, date, and day going clockwise and zone time going counter clockwise. The zone time result requires correcting for the difference between the observers longitude and the zone meridian.

    Use the red template to plot the Sun onto the 2102-D base disc with the current day's declination and time of meridional passage from the Nautical Almanac. Set Aries to month and day on plotting sheet, set red template to time of meridional passage, mark disc through slot at the correct declination.

    Now the 2102-D is ready to get civil twilight time and sky:

    1. Set Aries to month and day.
    2. Rotate latitude template so that the Sun is 5° to 10° below zero altitude.
    3. Read zone time of civil twilight and select stars.

    Image examples are for 12 October 2010
    -meridional passage Sun plot.
    -civil twilight template set.

    Greg Rudzinski
    NavList message boards and member settings: www.fer3.com/NavList
    Members may optionally receive posts by email.
    To cancel email delivery, send a message to NoMail[at]fer3.com



    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