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
    Name or NavList Code:
    Email:
       
    Reply
    Re: Index error by a star-star distance
    From: Bill B
    Date: 2008 Sep 22, 16:18 -0400

    Andres wrote:
    
    > I am writing an article about "Index error by a star-star distance".
    >
    > Unfortunately there is not much information about this subject, or I can't
    > found it. Anybody has any source of information; old books, papers, ... ?
    
    I have an Excel spreadsheet to calculate star-to-star distances.  It
    includes corrections for the observer's altitude above sea level, barometric
    pressure and temperature.
    
    Inputs are SHA (or GHA of planet), declination, and Hc of the bodies at a
    given time; plus altitude of observer, temperature and barometric pressure.
    
    I would be happy to send you a copy if you are interested.
    
    As to averaging, the SHA's of stars are a constant for all practical
    purposes over a 5 to 10 minute observation period, and the angular distance
    is not particularly sensitive to Hc changes.  If you pick a time and make
    observations plus/minus 5 minutes from that time any change in the angular
    distance would usually be far less than the ability of a man/sextant to
    measure it.
    
    If you program will run on a Mac OS, I would love to see it.
    
    Bill B
    
    
    --~--~---------~--~----~------------~-------~--~----~
    Navigation List archive: www.fer3.com/arc
    To post, email NavList@fer3.com
    To , email NavList-@fer3.com
    -~----------~----~----~----~------~----~------~--~---
    
    

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Get a NavList ID Code

    Name:
    (please, no nicknames or handles)
    Email:
    Do you want to receive all group messages by email?
    Yes No

    A NavList ID Code guarantees your identity in NavList posts and allows faster posting of messages.

    Retrieve a NavList ID Code

    Enter the email address associated with your NavList messages. Your NavList code will be emailed to you immediately.
    Email:

    Email Settings

    NavList ID 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