Thanks for the input and we have discussed bubble sextants at great length before and flight navigation too. I have half a dozen bubble sextants of various types. I am interested with your use of a bubble sextant at sea because most texts say, that due to the quick accelerations at sea, that the bubble sextant doesn't work too well. I have never tried using one of mine afloat. Greq Rudzinski might have some information about this usage.
Here is a link to a group of us using our bubble sextants:
http://www.fer3.com/arc/m2.aspx?i=111467&y=201001
and more can be found in the archives:
http://www.fer3.com/arc/sort2.aspx?y=201001su
http://www.fer3.com/arc/m2.aspx?i=114097
You may also find this of interest:
http://www.fer3.com/arc/imgx/Bubble-sextants-Precision-Astrolabe.pdf
I also have put up
a website discussing flight navigation with bubble sextants:
https://sites.google.com/site/fredienoonan/other-flight-navigation-information
https://sites.google.com/site/fredienoonan/
Welcome aboard.
gl
--- On Thu, 10/6/11, sjoquist.magnus@telia.com <sjoquist.magnus@telia.com> wrote:
From: sjoquist.magnus@telia.com <sjoquist.magnus@telia.com>
Subject: [NavList] Sv: Re: Sv: Re: Use of AH for professional navigation
To: NavList@fer3.com
Date: Thursday, October 6, 2011, 1:42 AM
I am talking about artificial horizons for marine sextants, shipboard use.
In teaching students how to astronav, I have also used buckets of water as reflecting device with very godd outcomes. The bucket horizon is of course useless on a moving vessel, but adds to the understanding of what corrections to apply and how the sextant works. It also gives the student the "YESSS"-feeling and adds to his/her interest for the Art of Navigation in general and the Art of Astro Navigation in particular.
Re-reading some of present and previous discussions on AH's I have the impression that the core subject is marine surface navigation, even if air-navigation and military uses also in a wider perspective surely is relevant for the question about what is "horizontal". Training in areas without visible horizon is one very important step towards being an Astro Navigator.
Sorry to all of You if I have misunderstood the topic at hand.
/Magnus
----Ursprungligt meddelande----
Från: garylapook@pacbell.net
Datum: 2011-10-06 09:53
Till: <NavList@fer3.com>
Ärende: [NavList] Re: Sv: Re: Use of AH for professional navigation
Are you talking about the type of artificial horizons we have been discussing, a horizontal reflecting surface, or are you talking about artificial horizon sextants?
gl
--- On Wed, 10/5/11, sjoquist.magnus@telia.com <sjoquist.magnus@telia.com> wrote:
From: sjoquist.magnus@telia.com <sjoquist.magnus@telia.com>
Subject: [NavList] Sv: Re: Use of AH for professional navigation
To: NavList@fer3.com
Date: Wednesday, October 5, 2011, 11:46 PM
Hi Gary -
Short answer is: Fine!
Source: Own experience from the early mid -80's and early -90's (large commercial vessels = quite stable platforms. Rolling yes, pitching yes, vibrations no!).
Sub-source: Reports from former "students" (cadets Royal Swedish Navy) who have tried out some quite advanced instruments during their astro-training weeks onboard GLADAN and FALKEN (Navy Schooners).
Longer answer: Assuming You "accept" a precision in position somewhat lesser (say around 5 NM uncertainty) than You would for daylight/twilight observations (say better than 2
NM) under good conditions, You are happy to have it onboard, although it can be hard to persuade the shipowner to include it in his standard equipment on his vessels).
Also: Takes a bit of training to get good sights, which is quite OK. Not a bad way to spend night-watches at sea.
Best,
Magnus
----Ursprungligt meddelande----
Från: garylapook@pacbell.net
Datum: 2011-10-06 08:17
Till: <NavList@fer3.com>
Ärende: [NavList] Re: Use of AH for professional navigation
How do these artificial horizons work on shipboard?
gl
--- On Wed, 10/5/11, Magnus Sjoquist <sjoquist.magnus@telia.com> wrote:
From: Magnus Sjoquist <sjoquist.magnus@telia.com>
Subject: [NavList] Use of AH for professional navigation
To: NavList@fer3.com
Date: Wednesday, October 5, 2011, 10:43 PM
Dear All -
AH's are not only for desert/Arctic Navigation or for backyard training.
They are also provide means for 24hour astronav on the High Seas.
(Combined with dark-vision telescope we are talking about costs around 10.000 USD or more which normally is out of range for private (or students) budgets)).
Best!
Magnus Sjoquist
(Thanking You All for very interesting reading on this and other matters).
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