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: Calculating the time when GHA is equals zero?
    From: Jeremy C
    Date: 2020 Mar 13, 05:22 -0700

    Hi Tony,

    To be honest, I didn't look at his numbers, I just solved the problem using the Almanac. 

    1.)       I would like to be able to do is solve for the TIME that the GHA of the Moon is “zero°/360°” on Wednesday, March 4, 2020 between the hours of 19.00.00UT and 20.00.00UT.  I don’t know how to set up the relationship that will yield the time when the GHA of the Moon = 0.

    So I cracked open my trusty Nautical Almanac to March 4, 2020 and found the 1900 UTC GHA hr to be 349-15.4 with a v-correction between 7.0 at 1900 and 6.9 at 2000.  Since I knew, based on the spread between the hour, the 000 GHA would be closer to 2000, i worked with the 6.9.    

    I didn't even really look closely at the 2000UTC GHA but it's 3-41.4 (3.69 deg), for a difference of 14-26.0.  I don't use the hourly difference when using the NA for such things, so I just calculated it now.  Steve will have to tell us where he obtained his numbers because they don't match the NA.


    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