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: How accurate are fixes in practice?
    From: Frank Reed
    Date: 2008 Jul 13, 14:34 -0400

    Jeremy, you wrote:
    "My normal Celnav fixes are usually within 3 nm and I am disappointed by
    worse results.  Sunlines are usually within 1 nm when I use the GPS fix as
    the AP, as are LAN observations."
    
     From anecdotal evidence consisting of conversations with ocean navigators,
    this appears to be about normal for observations under "good conditions"
    with a good metal sextant and no shortcuts in sight reductions. The standard
    deviation error in individual sights (judging from the offset of LOPs from a
    GPS position) appears to be roughly 1 minute of arc, implying that about
    two-thirds of LOPs are within 1 nautical mile. The distribution appears to
    have some "kurtosis" meaning that there's more likelihood of larger errors
    than a plain normal (Gaussian) distribution would imply, but it's
    manageable.
    
    So what are "good conditions"?
    
     -FER
    
    
    --~--~---------~--~----~------------~-------~--~----~
    Navigation List archive: www.fer3.com/arc
    To post, email NavList@fer3.com
    To unsubscribe, email NavList-unsubscribe@fer3.com
    -~----------~----~----~----~------~----~------~--~---
    
    

       
    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