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: Sundog
    From: Frank Reed
    Date: 2013 Feb 16, 15:39 -0800

    Bill B, you wrote:
    "Of importance Frank did not specify this is the sundog he saw, but rather the sundog YOU are facing."

    Yes. That was the idea. It was a little puzzle inspired by the photo. This is something that can, in fact, happen. You're out for a walk in the woods near sunset. You see a sundog but can't see the Sun. If you know enough about the Sun's position in the sky, then you can get a pretty decent azimuth, within a degree or so. Another similar case involves determining the Sun's altitude and azimuth when you can see a rainbow, but the Sun itself is not visible for some reason. It's the same idea. A rainbow has a fixed angular relationship with the Sun in the sky. This isn't navigation quality material. It's more about having a quick sense of orientation from some basic knowledge of sky phenomena.

    "To me this means MY sundog could be at any longitude I specify near
    sunset."

    Right. It makes little difference as long as we're talking about observers in the continental US (which I should have specified). The Sun's declination only changes by a few minutes of arc between sunset on the east coast and sunset on the west. Given the single degree precision of the inputs that I specified, and given the rather approximate ability to decide where a sundog begins or ends, that change in declination makes no difference. Even in other longitudes, it would barely matter.

    For Antoine, is there a common name in French for a "sundog"?

    -FER
    ----------------------------------------------------------------
    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?

    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