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    Re: Fix by Occultations
    From: Brad Morris
    Date: 2009 Feb 7, 15:56 -0800

    Hi George
    
    You can find the low precision values of the Ecliptic Latitude and Longitude 
    of the Moon in the Astronomical Almanac.  The published values are to two 
    decimal places of degrees.
    
    If you go to
    http://asa.usno.navy.mil/SecD/LunarPoly.html
    you will find the co-efficients to the Lunar Polynomials.
    
    When you use them, you will derive the high precision RA, declination and HP.  
    The results can be converted (as you point out) to Ecliptic Latitude and 
    Longitude.
    
    One issue I found, however, is that I had to add 180 degrees the ATAN function 
    provided to obtain correlation.  That is, the equation reads
    
    Ecliptic Long = 180 + atan(((sin(RA)cos(ObliquityEcliptic) + tan(dec)sin(ObliquityEcliptic))/cos(RA))
    
    EXAMPLE
    7June09
    
    Polynomial Coefficients
    RA
    245.4302085
     13.3954668
      0.0795003
     -0.0392653
     -0.0030594
      0.0007151
    
    Dec
    -25.6866823
     -1.3663138
      0.6207190
      0.0099947
     -0.0035461
     -0.0000342
    
    HP
     0.91121504
    -0.00532634
     0.00057368
     0.00001426
     0.00000293
    
    YIELDS (at midnight, we can easily shift the time)
    RA 245.4302085
    Dec -25.6866823
    HP 0.91121504
    
    CONVERTING TO ECLIPTIC LAT LONG
    Elip Lat -4.110005927
    Elip Long 247.9338333
    
    
    The Astronomical Almanac 2009 publishes the 0h TT data as
    
    RA 16h 21m 43.25s
    Dec -25d 41m 12.1s
    HP 54m 40.37s
    
    Ecliptic Lat -4.11
    Ecliptic Long 247.93
    
    It seems to be worth while to go through the polynomial expansion, 
    particularly if we intend to include the Limb Effects (mountains) like Frank 
    suggests.
    
    Best Regards
    Brad
    
    
    
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