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Calc - Updating for IERS Conventions (2010): Precession/Nutation – change to use IAU2006 precession model. Makes a difference of ~0.5 µas/yr from 2000.0.
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Calc - Updating for IERS Conventions (2010): • Precession/Nutation – change to use IAU2006 precession model. Makes a difference of ~0.5 µas/yr from 2000.0. • Add and/or modify UT1 and polar motion libration model (formerly called short period nutation effects). Typically a few µas effect on EOP’s, sub-psec effect on delays. • Pole Tide – new mean pole model. • Ocean loading – calculate new coefficients. • Ocean pole tide loading (new model). Effect is typically no larger than 1.8/0.5/0.5 mm in U/E/N. • Antenna thermal expansion model - ? [In Solve] • Pressure loading and S1/S2 atmosphere tides - ? [In Solve] • VMF - ? [In Solve]
Plans/Wishlist for Calc: • Update to version 11: • For IERS Conventions (2010). • Finite distance model • Thermal deformation (?) • Pressure loading (?) • VMF (?) • ????? • Modify inputs/outputs for νSolve and DiFX. • Create C++ version.
Other Issues: Work with VLBA and/or other DiFX users for efficient use Of Calc. If processing time becomes an issue, several things can be done. Usage can be structured or computations saved to avoid re-computing the same things many times. Unused time derivatives and partials computations can be removed.