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: Daytime Venus Rising Dip Short
    From: Gary LaPook
    Date: 2012 May 5, 21:59 -0700
    I have attached two photos. IMG 8895 is a view through the Kollsman periscopic sextant and 8887 is a view through my Pioneer A-7. Some bubbles in various octants are opaque as in the A-7 so you line up the body with the side of the bubble while others are clear and you center the body in the bubble. See:https://sites.google.com/site/fredienoonan/resources/aircraft-navigation-manual-h-o-216-1941/ho216-1941-180.jpg?attredirects=0

    and https://sites.google.com/site/fredienoonan/topics/pionneer-octant


    --- On Sat, 5/5/12, Alexandre E Eremenko <eremenko@math.purdue.edu> wrote:

    From: Alexandre E Eremenko <eremenko@math.purdue.edu>
    Subject: [NavList] Re: Daytime Venus Rising Dip Short
    To: NavList@fer3.com
    Date: Saturday, May 5, 2012, 10:34 AM


    > In this image the camera gives something other than what the eye is seeing.
    > I see a red circle for the Sun that includes the pictured halo.

    Yes, but there is another strange feature: the bubble looks like a ring
    indeed, but the ring is excentric!
    I suppose you align the Sun with the outer circle, ignoring the inner one.
    In my sextant the bubble looks  like a good, concentric ring,
    I make the INNER circle slightly larger than the Sun, and align
    the Sun with the inner circle.

    Perhaps I am doing wrong, and I have to make smaller bubble,
    ignore the inner circle and align with the outer one??




    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