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: Ratio of variances
    From: Greg Rudzinski
    Date: 2018 Nov 2, 08:30 -0700


    With experience you can call the shots which means that a navigator can give a weighted percentage to the quality of the observation. The horizon sharpness, late twilight, cloulds, rough weather, stability of vessel,  optics power/clarity, and sight reduction method used are some of the factors to consider when putting a confidence percentage on an observation. Sometimes all that is available will be two low confidence sights separated by a narrow azimuth cut.  The fix error circle would then be large (lets say >6nm radius as an example). An example of high confidence would be four observations seperated by 90° using an artificial mercury horizon all at the same altitude of lets say 25°. The error circle would be very small (< 0.5nm).

    Greg Rudzinski

    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