fk5hip, r5h, s5h
[SOFA] Returns the FK5-to-Hipparcos rotation
r5h and spin
p_Hipparcos = r5h p_fk5, where
p_Hipparcos is a p-vector in the Hipparcos frame and
p_fk5 is the equivalent FK5 p-vector.
s5h is the
time derivative of the FK5-to-Hipparcos rotation, measured in radians
per Julian TDB year.
r5h has 3 by 3 elements,
s5h has 3 elements.
See also: Astronomical Coordinate Calculations