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: Standard sea level temperature and pressure
    From: Gary Harkins
    Date: 2003 Jan 13, 17:59 EST
    In a message dated 1/13/2003 5:27:54 PM Eastern Standard Time, marc.bernstein@ATT.NET writes:

    Are the constants in the equation for calculating refraction set so that refraction is 0 at 10C/1010mb? If so they could also have been chosen to make it 0 for 15C/1013mb?

    They can't be...refraction is an actual measurement of how much the atmosphere is bending light rays.  10C/1010mb has to cause NO additional bending of the light rays, not just a reference.  If you compare column A with column N on any given row you will see that the values are the same, just opposite signs.  If the values were different then I would say that 10C/1010mb was just a convenient reference.  But since they are the same I would say that 10C/1010mb and other representations in G are causing no additional bending of the light.

    Gary Harkins C400 #140 "Cygnus"
    Website   http://www.hometown.aol.com/htycgary/myhomepage/index.html
    Harbour Towne Marina, Muskegon, Michigan Slip C-28
    Harbour Towne Yacht Club, Life Member
    C400 National Association
    United States Power Squadrons-JN

    NRA Life Member
    MCRGO (Michigan Coalition for Responsible Gun Owners)
    JPFO (Jews for the Preservation of Firearms Ownership)
    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)