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pr00, jdtt, dpsipr, depspr
[SOFA] Returns the precession-rate part of the IAU 2000
precession-nutation models (part of MHB2000), for the specified TT
Julian Date jdtt. Returns the nutation in longitude
dpsipr and obliquity depspr in radians with
respect to the J2000.0 equinox and ecliptic. The output variables get
the same dimensions as jdtt.
The MHB2000 model does not specify which set of Euler angles to use to
express precession. The most literal and straightforward procedure is
to adopt the 4-rotation epsilon_0, psi_a,
omega_a, and xi_a. Then dpsipr can be
added to psi_a, and depspr to both omega_a
and eps_a.
See also: Astronomical Coordinate Calculations