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: Centring Error Detector
    From: Brad Morris
    Date: 2014 Jan 22, 15:05 -0500

    Frank

    Your idea of using the sextant has been well discussed and does have merit.  The ideal sextant can be set to any arbitrary angle.  All you need is an ideal sextant or one in which all errors are *known*.  Then all of the observed errors can be attributed to the measured sextant. Failing that, the truth remains hidden.  The observed errors will be a hodge podge of errors in the ideal sextant and errors in the measured sextant.

    The beauty of an ultradex is the precision it affords while permitting easy manipulation.  Here's one on eBay right now http://m.ebay.com/itm/191042953903?nav=SEARCH&sbk=1 the top plate and bottom plate engage with a patented interface, that guarantees accuracy and repeatability.  It is an independent NIST traceable, calibrated instrument.  That is something simply not achievable with your sextant concept, attractive as it may be.

    The top and bottom plates of the ultradex  are set parallel to the plane of the sextant.  The beam splitter (or prism or mirror) mounts perpendicularly to that, just like an index mirror.  So rotating the ultradex top plate rotates the horizon optical path. 

    Take a look at this arrangement
    http://www.globalspec.com/reference/14523/160210/chapter-2-2-beam-splitter.

    In place of the collimator put the sextant to be measured.  In place of the mirror 1, is the horizon path disturbed. In place of mirror 2 is the horizon path, undisturbed.

    Perhaps this will engender a more meaningful response

    Brad

    On Jan 22, 2014 1:33 PM, "Frank Reed" <FrankReed@historicalatlas.com> wrote:

    Brad, you wrote:

    "If you followed that, then you know this is awesome in comparison to the Kew certificates. I just haven't figured out how to align the beam splitter plate to zero"

    You can do that with any room-temperature superconducting photonic matrix. Or so they say...

    -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
    ----------------------------------------------------------------

    : http://fer3.com/arc/m2.aspx?i=126626

       
    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