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: Instumental error?
    From: Bill B
    Date: 2005 Apr 21, 00:02 -0500

    > Bill wrote:
    > "> If I recall, the specs
    >> are plus/minus 10 seconds error along  the arc (0.17').
    >> Unless you got a
    >> dud, any value higher than  0.2' is highly suspect.
    > And Alex replied:
    > "Yes, I'm afraid it is a dud."
    Frank responded:
    > I don't buy it. That the certificate *says* the error is 10 seconds doesn't
    > mean much of anything. Arc error is a correctable error and shooting
    > lunars/star-star sights is probably the best way to detect it. Build your
    > table,  and
    > then use it. And the fact that such error exists doesn't mean the instrument
    > is a "dud". Correcting for arc error, once you have determined it, is every
    > bit  as easy as correcting for index error.
    I was looking at the bigger picture (for a refreshing change of pace).
    Celestaire, for example, speaks of accuracy by the lot.  I would expect my
    Atsra III B to be no worse than plus/minus 19" throughout the arc, maybe
    better, despite any certificate.  Any Cassens & Plath no worse than
    plus/minus 9".  Any SNO-T no worse than plus/minus 10".  Those should be
    upper limits.  That is not to say lemons do not exist.
    I have no cause to believe Soviet military gear would have been substandard
    (although not petite ;-)  If I accurately recall the post, some sort of cel
    nav contest was won by a Polish sailor with a SNO-T--a long run of .2'
    within known positions.  If any of the list members have more details about
    this seagoing cel-nav superstar, I would love to read them.
    > I don't buy it.
    Too bad.  I have a gut feeling Alex would be willing to sell it if the
    "right" offer came along.   Kidding aside, I believe him to be the sort
    that will persevere and defeat any idiosyncrasies the SNO-T may posses.

    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