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    Re: 1901 May, 22 Lunar example by French Navy Captain Arago
    From: Antoine Couëtte
    Date: 2010 Feb 22, 22:10 -0800

    23 Feb 2010

    Dear Sir,

    Sorry for me not being able to write directly your name since as being a newcomer to this Navlist forum I have not kept track of all "coded names", especially with some single contributors apparently using more than one "coded name".

    One of them might even have ended up with 3 different "code names".

    Read me Jeremy ??? :-))


    First of all, I would not like to forget thanking you for your quick reply in Navlist # 11769 Date: 4 Feb 2010 12:37 to a query of mine.

    I acknowledge that I still have in my pending "to do list" a bit of research to perform before I can adequately reply to your following remark in your same Navlist # 11769 post :


    Note, there is an apparent typographical error in the "calcul de l'heure de paris par une distance lunaire" example of Arago. the "formules." for both RA and Dec have the second term shown as sin squared. it seem is should be sin of twice the angle. (see for example Chauvenet)


    BTW, it looks like you keep replying almost instantly to requests for contributions, whether specifically directed to you or not ... So, Well done ! :-)) ... and Thank you !!!


    At last to our main topic for to-day !

    Thank you very much for the results you gave me for the Aldebaran occultations on 1997 Oct, 19 computed by 2 different software.

    In http://www.fer3.com/arc/imgx/f1-occ-001.jpg, you indicate a Disappearance at UT=07:44:47 and a Reapparence at UT=09:02:50, and

    in http://www.fer3.com/arc/imgx/f1-occ.jpg, you indicate a Disappearance at UT=07:44:48 and a Reapparence at UT=09:02:50. Just one question : this one file possibly shows as incomplete since some numbers right after the rightmost "Cct" column seem to be (partially?) missing. Are they of some special significance for my use ?

    When compared to my computed data - UT=07:44:47.3 for Disappearance and UT=09:02:51.2 for Reapparence - the numbers you just provided show a very good agreement between all results, or at least an agreement which is well inside/within the computation accuracy criteria and objectives I had initially set up for my Occultation/Lunar program : make it consistent with the very best sextant distances determinations/accuracies, i.e. +/- 0.1' on measured angles or @ +/- 12 s on elapsed time in the very best cases.

    Thank you again so much and Have a Great day !

    Antoine M. "Kermit" Couëtte
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