NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Antoine Couëtte
Date: 2011 Feb 12, 06:04 -0800
RE :
http://www.fer3.com/arc/m2.aspx?i=115630
[NavList] Re: Friendly challenge : Jupiter Lunar Exercise 09 Feb 2011
From: FrankReed---com
Date: 11 Feb 2011 21:34
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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.
OUR COMPARED RESULTS :
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.
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Displaying such actual Hourly Variation on your OLC would probably (greatly?) enhance its usefulness to potential Users. What do you think of this suggestion ?
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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.
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Thank you for your Kind Attention, and
Best Regards to all
Kermit
Antoine M. "Kermit" Couëtte
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