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: Old Style Lunar
    From: Frank Reed CT
    Date: 2005 Jan 11, 15:02 EST
    "The airport elevation at Rocky Mountain House, Alberta is 3,242 feet."
     
    Which would decrease refraction values (absolute values) for all altitudes below 45 degrees by more than a tenth of a minute of arc --and increasing to 0.5 minutes of arc at 10 degrees altitude (10% of the standard sea level values). Did Thompson correct for this? Most accounts of lunars were written for observers at sea level, literally. Of course, if he measured barometric pressure at all, I suppose it would necessarily have been with a barometer calibrated at low altitude which would account for refraction at mountain altitudes automatically (assuming he had tables that covered such low pressures).
     
    -FER
    42.0N 87.7W, or 41.4N 72.1W.
    www.HistoricalAtlas.com/lunars
       
    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