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    Re: Time of meridian passage accuracy
    From: Antoine Cou�tte
    Date: 2009 Oct 2, 00:03 -0700

    Dear Frank,
    
    
    In reply to your post in [NavList 10031], I am very sorry that in [NavList 
    10014] I have messed up with your files arrangement and title logics. I 
    thought that with the site architecture it would be helpful to other readers 
    to title-specify which post(s) I was replying to.
    
    Promised ! I won't do it again.
    
    Therefore you may as editor remove [NavList 10014] since I have observed that 
    from time to time apparently some files might have been removed. Please 
    accept my most sincere my apologies.
    
    And I am submitting again here-under my query which was first stated in [NavList 10014].
    
    ********************************************************************
    
    Dear Gary, Jim and Andres,
    
    
    
    
    First of all, and since the Data first published in [NavList 10009] have been 
    computed/derived and published by Gary and not by Jim, I earlier 
    misinterpreted this and I am sorry for this misunderstanding. Apologies to 
    both of you Jim and Gary.
    
    *******
    
    I again regret that the "unclear/messy" appearance of my post [NavList 10014] 
    might has concealed the MAIN POINT I have adressed and which I am summarizing 
    here-under with new words. Sorry for the "strict" presentation with (1) , (2) 
    , ... but I hope it helps grasping the subject better and thus helps readers' 
    attention.
    
    (1) - First in [NavList 10009] Gary submitted data to the Community and 
    requested from us some feedback on these data, essentially as regards the 
    difference between LAN and Culmination times in his example.
    
    (2) - Andres subsequently analysed Gary's data [NavList 10014] and - from his 
    statement "mean square error 0.000265" which I interpret as being 0.000265 
    Degree - he seems to find that these data derived by Gary almost EXACTLY 
    match a second degree parabola.
    
    (3) - From my own interpretation of Andres's results, - is it correct ? Please 
    Andres be so kind as to tell me - and starting from Andres' LAN time and 
    position, I then recomputed/derived all the Observer's positions at the 
    various specified times listed by Gary. I have based my computation on the 
    300 kt south speed indicated by Gary. For each observation time given by Gary 
    and each position deduced from my interpretation of Andres' results, I have 
    computed what should be the Sun center geocentric apparent height (and also 
    Azimuts) values, thus getting for each position and time a "computed height" 
    directly comparable to Gary's published height for the very same time. I 
    repeated this calculation over the entire 25 shot set and published my 
    results to be independently verified by anybody in the community.
    
    *******
    
    So I am just (again) requesting that all my published results be independently 
    CROSSCHECKED AND VERIFIED ON THE FOLLOWING POINTS :
    
    a - Is my understanding of Gary's published height as being "Apparent 
    Geocentric Sun Center coordinates" correct ? I believe so, but if I have 
    totally misundertood Gary's helful comments in [NavList 10013], then all this 
    lenghty post and all the lenghty computations and work which are behind it 
    are totally useless and VOID. The END !!!
    
    b - Is my own interpretation of Andres's results correct ? This point 
    essentially covers the fact that apparently the data published by Gary seem 
    to be an almost perfect parabola. I already have had kind direct exchanges 
    with Andres and I am sure he will explain this to me. Thank you in advance 
    Andres.
    
    c - Assuming that my interpretation of Andres's results is correct, could 
    somebody crosscheck that my 25 subsequent positions derived for the 25 times 
    of Gary's observations are in accordance with Andres' results ? This is a 
    rather simple crosscheck and I thank whoever will do this.
    
    d - Assuming that all these 25 positions recomputed from Andres's results are 
    correct, could somebody (else?) crosscheck that from the 25 positions 
    obtained at the times of Gary's published observation times the Geocentric 
    heights I am computing are correct ? Bigger task and Thank you to whoever 
    will do this also.
    
    *******
    
    To this point, and assuming that my computations so far have been all correct, 
    I come to the necessary conclusion that there can be NO MATCH between my 
    reconstructed data and Gary's published data.
    
    Apparently and - according to my interpretation of Andres's results - Gary's 
    published data seem perfectly symmetrical (a 2nd degree parabola) if 
    considered from the Culmination time.
    
    From the onset I have personnally felt that this feature seems highly 
    improbable given the high N/S Observer's speed component. This personal view 
    point is also supported by Jim's comment posted meanwhile in [NavList 10030].
    
    As a conclusion, and in addition to Peter Hakel's very same request in 
    [NavList 10027], I would like very much that Gary be so kind as to publish 
    the exact method he used to derive the data he submitted to all of us. The 
    Data he published meanwhile with more significant digits [NavList 10035] are 
    not sufficient for this purpose. Such full explanations by Gary will be a 
    very welcome complement to this most interesting thread.
    
    Thank you very much in advance Gary, and Best Regards to you all from
    
    Antoine
    
    
    Antoine M. "Kermit" Couette
    
    
    *************
    
    NOW, YOU WILL FINF HEREUNDER THE DATA EXPLAINED HERE-ABOVE WHICH I 
    "RECONSTRUCTED" FROM ANDRES' POSITION AND GARY's TIMES.
    
    
    NOTE 1 : Here "Hs" has the exact same meaning as "Ho" in Gary's data,
    
    NOTE 2 : ALL the question marks "?" appearing herunder are to be interpreted 
    as symbols for "d" or "Degree". For definite lack of time, I only corrected 
    the first line.
    
    NOTE 3 : Rightmost column should read "Gary's Data" (i.e. published heights Ho) instead of "Jim's data"
    
    Times Lat      Lon       Geoc. Ho    Azimuts    Gary's Published Ho's 
    
    17:00 N24d09'8 W078d30'0 Hs=42d18'1  Z=176.0d  Jim's data : Hs = 42d14'
    17:05 N23?44'8 W078?30'0 Hs=42?46'9  Z=177.6?  Jim's data : Hs = 42?44' 
    17:10 N23?19'8 W078?30'0 Hs=43?13'8  Z=179.1?  Jim's data : Hs = 43?13'
    
    17:15 N22?54'8 W078?30'0 Hs=43?38'9  Z=180.7?  Jim's data : Hs = 43?39' 
    17:20 N22?29'8 W078?30'0 Hs=44?02'1  Z=182.3?  Jim's data : Hs = 44?04'
    17:25 N22?04'8 W078?30'0 Hs=44?23'3  Z=183.9?  Jim's data : Hs = 44?26' 
    
    17:30 N21?39'8 W078?30'0 Hs=44?42'5  Z=185.6?  Jim's data : Hs = 44?47' 
    17:35 N21?14'8 W078?30'0 Hs=44?59'5  Z=187.2?  Jim's data : Hs = 45?06'
    17:40 N20?49'8 W078?30'0 Hs=45?14'5  Z=188.9?  Jim's data : Hs = 45?22'
    
    17:45 N20?24'8 W078?30'0 Hs=45?27'3  Z=190.6?  Jim's data : Hs = 45?36'
    17:50 N19?59'8 W078?30'0 Hs=45?37'9  Z=192.2?  Jim's data : Hs = 45?49'
    17:55 N19?34'8 W078?30'0 Hs=45?46'3  Z=193.9?  Jim's data : Hs = 45?59'
    
    18:00 N19?09'8 W078?30'0 Hs=45?52'4  Z=195.6?  Jim's data : Hs = 46?06'
    18:05 N18?44'8 W078?30'0 Hs=45?56'2  Z=197.3?  Jim's data : Hs = 46?12'
    18:10 N18?19'8 W078?30'0 Hs=45?57'8  Z=199.0?  Jim's data : Hs = 46?15'
    
    18:15 N17?54'8 W078?30'0 Hs=45?57'1  Z=200.7?  Jim's data : Hs = 46?16' 
    18:20 N17?29'8 W078?30'0 Hs=45?54'1  Z=202.4?  Jim's data : Hs = 46?14'
    18:25 N17?04'8 W078?30'0 Hs=45?48'8  Z=204.1?  Jim's data : Hs = 46?10'
    
    18:30 N16?39'8 W078?30'0 Hs=45?41'3  Z=205.7?  Jim's data : Hs = 46?04' 
    18:35 N16?14'8 W078?30'0 Hs=45?31'5  Z=207.4?  Jim's data : Hs = 45?56'
    18:40 N15?49'8 W078?30'0 Hs=45?19'5  Z=209.0?  Jim's data : Hs = 45?45'
    
    18:45 N15?24'8 W078?30'0 Hs=45?05'3  Z=210.6?  Jim's data : Hs = 45?33'
    18:50 N14?59'8 W078?30'0 Hs=44?49'0  Z=212.2?  Jim's data : Hs = 45?18'
    18:55 N14?34'8 W078?30'0 Hs=44?30'6  Z=213.7?  Jim's data : Hs = 45?01'
    
    19:00 N14?09'8 W078?30'0 Hs=44?10'1  Z=215.2?  Jim's data : Hs = 44?41'
    
    
    
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