Don Casey - Dragged Aboard Storm Tactics Handbook:
Modern Methods of Heaving-To for Survival in Extreme Conditions
by Lin Pardey and Larry Pardey


      

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Horizons and levels

From: Royer, Doug (no email)
Date: Tue Jul 15 2003 - 14:11:00 EDT

  • Next message: Fred Hebard: "Re: Artificial Horizons and Mercury."

    Just want to get a couple of more ideas before I leave.I also want to
    explain what and why I did it.As for the 3 vs. 4 leveling bolts,maybe 3 are
    better or at least easier to use to level the reflective surface.It takes
    45-90 sec. to level my horizon and can be frustrateing to get it level.It
    appears that with 3 bolts the leveling will be faster and just as good.The
    spirit levels I bought are round,the size of a 25 cent coin and have a
    circle inscribed or printed on the convex plastic lens a little smaller than
    the size of a dime.They only cost $2.50 each,so they aren't very accurate or
    I should say they can't give that fine of a reading.However,the little
    system that was made at least proves to me that this is a viable alternative
    to liquid levels.I leave it to you guys to hash out the finer details of
    makeing it more accurate.Once this thing,and the glass one I made, is
    leveled(relative)I can view all bodies untill they move so much as to need
    to reposition the horizon.The Sun and Moon were observed.Last week I
    observed the daytime Moon with the glass horizon I
    made.Spica,Arcturus,Deneb,Altair,Vega and Antares were observed.Last night I
    observed Nunki(with the glass horizon and the MS- 733) untill the light from
    the riseing Moon washed it out.The question is how accurately must it be
    leveled?I started building a horizon because of frustrations useing a Davis
    horizon in strong winds during backpacking trips.I use a Davis M-25 plastic
    sextant on these trips and get an accuracy from the sextant as + - 0.2' at
    the very best.I'm just pleased as punch getting a fix within 0.5 mile of the
    gps pos. useing the above set-up.At home useing the above horizons and the
    MS-733 sextant I get finer results but that is to be expected.My main goal
    in this was to see if one can get good refections of stars or planets with a
    glass or plexiglas horizon,be fairly easy to use and be light in wieght.At
    least to me,these practical experiments prove it is all the above.


  • Next message: Fred Hebard: "Re: Artificial Horizons and Mercury."



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