ly, the velocities of the
      target and observer relative to the solar system barycenter at
      the epochs et+lt and `et'.

      If correction for stellar aberration is requested, the target
      position is rotated away from the solar system barycenter-
      relative velocity vector of the observer. The rotation is
      computed as in the reception case, but the sign of the
      rotation angle is negated.


   Precision of light time corrections
   ===================================

      Corre