EarthRotationZero:

Path: SC/Ephem

% Determine jD for when the earth-fixed frame is aligned with the ECI frame. 
   The input JD gives the day of interest.
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   Form:
   jD0 = EarthRotationZero( jD, eOfECalc )
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   ------
   Inputs
   ------
   jD          (1,1 Julian date
   eOfECalc    (1,1 Calculate the equation of the equinoxes

   -------
   Outputs
   -------
   jD0         (1,1 Julian date at which theta is zero

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   References: Seidelmann, P. K., Explanatory Supplement to the 
               Astronomical Almanac,  University Science Books, 1992, p. 20.
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Children:

SC: Ephem/EOfE
SC: Ephem/GASTime
SC: Ephem/GMSTime
SC: Ephem/MSidDay
SC: Ephem/NutDelta
SC: Ephem/ObOfE
Common: Time/DTSToDTA
Common: Time/Date2JD
Common: Time/JD2000
Common: Time/JD2T
Common: Time/JDToMidnight
Math: MathUtils/R2P5
Math: Trigonometry/CosD
Math: Trigonometry/SinD

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