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: Extremely poor conditions??
    From: David Fleming
    Date: 2012 Mar 21, 08:10 -0700

    The errors in the observed altitues imply observations were smaller than predicted.

    We know that sun observed with LL touching horizon horizon is actually just below horizon. That is the sun LL is seen 30 min higher in sky than it is. This means that usual conditions also raise the apparent horizon by the same 30 mins or the visible horizon is further than the geometric horizon.

    The atmosphere is the cause of this refraction, the more air the more bending.
    Normal surface temperatures bend terrestial rays 30 min. A colder surface air layer would be denser, oep, and would therfore haise the horizon further producing smaller than expected altitudes.
    ----------------------------------------------------------------
    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
    ----------------------------------------------------------------

       
    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