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    Re: New ways to create false horizons?
    From: Paul Dolkas
    Date: 2017 Jul 20, 17:05 -0700

    There are digital inclinometers that are pretty accurate, cheap and fairly reliable, and far more accurate than what’s in your cell phone. They use MEMS technology, which is explained in the link:  www.posital.com/en/products/inclinometers/mems/MEMS-Technology.php.


    I think the only reason  why somebody hasn’t develop a really a good digital sextant using one of these is that with GPS, it’s no longer needed.   (Well, on THIS planet, anyway)


    -Paul Dolkas


    From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Pete Solon Palmer
    Sent: Thursday, July 20, 2017 3:14 PM
    To: paul@dolkas.net
    Subject: [NavList] Re: New ways to create false horizons?


    Hi Noell,

    Thanks for sharing your experience with the ball bearing.  I agree that this method will never be very accurate.  While fooling around with my Mercury switch, I noticed that it was impossible to keep the light lit (level) for a sustained moment, but it would blink every time it was level.  This gave a good idea where level was, better than trying to estimate it while looking into a fog bank, but not good enough for precise work.


    Maybe there is an electronic AH solution.  The sensors (mag, gyro, accel, gravity) in my smart phone seem to be less accurate than a ball bearing and a toy compass, so I don't see a solution involving phones soon. 


    There are some interesting little modular computers available with add-ons such as Bluetooth, sensors, and time.  I'm thinkin' what if I put a mag sensor on the sextant frame, a gravity sensor on the index arm, then wire it up to the Mercury switch.   Whenever the switch was level, it would take a sight (Hs, Az, and GMT) and send it to the phone by Bluetooth.  Sort of like an averaging sextant, except that it would only record a sight when it was level.  The Mercury switch seemed to be very accurate (no friction or dust) at determining level, but it moved so fast (wild blinking of the light) that it was hard to get an average.  In steps the computer that is faster than the human eye.  It takes a sight only when the sextant is level on the plane of the sight, and sends it to the phone.  I guess it depends on how good the sensors are.


    Anyone have any opinions? I'm in a life long quest for the best AH, since in my experience, the lack of a clear horizon seems to be the Achilles Heel of Astro Nav.


    Celestaire has a neat cardboard sextant with a spirit level.  This could be ideal for the training academy.



    -----Original Message-----
    From: Noell Wilson <NoReply_Wilson@fer3.com>
    To: globenav <globenav---.com>
    Sent: Wed, Jul 19, 2017 1:30 pm
    Subject: [NavList] Re: New ways to create false horizons?

    Hi Pete,
    I tried using a new chromed ball bearing to indicate level on a mirror artificial horizon (AH). The plan was that one simple steel ball on the mirror could substitute for a precision level and, when the ball stopped rolling, the mirror would be perfectly level.
    It didn't work.
    Dust or stiction or something kept the ball from rolling until the mirror was tilted way out of level.

    I don't think your curved tube with a steel ball and proximity switches is going to be very accurate.
    Regards, Noell

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