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: Angular Distance Between Stars By Camera and Sextant
    From: Greg Rudzinski
    Date: 2012 Sep 18, 12:43 -0700


    If you look at my original results:

    Alioth Alkaid Hc 31*37*
    10* 27.1' observed distance by sextant
    +0.3' refraction correction by table
    10* 27.4' true distance
    10* 27.6' true calculated distance by William's on-line calculator
    Low 0.2'

    You will see that the true distance William's calculation using USNO data is 10* 27.6' vs. Paul's true distance calculation 10* 27.66' for a difference of .06'. Not much of a difference. What you see listed as true distance in my original post is the sextant distance reading corrected to true by adding a refraction correction of 0.3'. The difference between my corrected to true sextant observation and the calculated true distance is 0.2' so my sextant was reading low 0.2'. This means that an index correction of 0.2' needs to be added to the sextant reading. It looks like everyone has close to the same numbers.

    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