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    Re: Friendly challenge : Jupiter Lunar Exercise 09 Feb 2011
    From: Antoine Couëtte
    Date: 2011 Feb 12, 06:04 -0800

    RE :
    [NavList] Re: Friendly challenge : Jupiter Lunar Exercise 09 Feb 2011
    From: FrankReed---com
    Date: 11 Feb 2011 21:34


    Dear Frank and Dear all,

    Thank you Frank for your extremely interesting Reply and Solution to my recent "Friendly Jupiter Lunar Challenge".

    I agree with everything you said and I also enjoyed very much the opportunity to benefit from your SUPERIOR Teaching talents !!!

    And, no need to say : YOUR ANSWER IS RIGHT ON THE SPOT.

    Yes ! This Lunar should certainly be regarded as a "Modern" Navigation exercise, rather than a "classical" Lunar.

    It nevertheless shows that WITH ONLY a Time Keeper, and a good Sextant, you can locate yourself anywhere on Earth with a quite acceptable accuracy, provided you have excellent environmental conditions.

    Since you so kindly replied to my Challenge, I am hereby publishing a Solution to this Lunar which higly relies on the use of your excellent Lunar On-Line Computer. It uses the same basic principles you just so well explained and I took the time to explicit (almost) all computations for interested readers.
    This document is provided under the attached ".pdf" format.


    Compared to your position :

    Latitude: 46d 42.4'N, Longitude: 2d 26.0'W, GMT: 18:07:30 (watch error 16:00:12)

    the results I am deriving through the extensive use of your OLC are :

    Latitude: 46d 43'1 N, Longitude: 2d 26.2'W, GMT: 18:07:27 (watch error 16:00:09).

    My actual position was very close from : N 46°42'9 and W 002°23'7 (Threshold of Runway 04 Ile d'Yeu Airport LFEY).

    As you will notice, I was able to get quite fast converging results thanks to the use of the Centers Distance actual hourly variation (28'.72 in this case) which I had to independently determine.


    Displaying such actual Hourly Variation on your OLC would probably (greatly?) enhance its usefulness to potential Users. What do you think of this suggestion ?


    Anyway, it was a lot of fun ...

    As I will embark later this afternoon, evening and to-night to ferry a Sea Cruiser in our area, if weather permits, (so far so good ...) I am planning to do the same Lunar exercise with just my sextant and my wristwatch. Results will be interesting since this will be a (fast) moving platform with expected various course and speed changes. I am just curious to see what kind of results I can get. If any other Reader / NavList Member interested I can also publish the data pertaining to this upcoming/expected Lunar when I am back home.


    Thank you for your Kind Attention, and

    Best Regards to all


    Antoine M. "Kermit" Couëtte

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