Chapter 5: Transformation between the International Terrestrial Reference System and Geocentric Celestial Reference System
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- Routines that support the transformations described in Chapter 5 (see Section 5.9) are included in the SOFA collection.
- PMSDNUT2.F -
Subroutine to compute the diurnal lunisolar effect on
- Based on the subroutine PMsdnut. Differences between the two subroutines are typically smaller than 0.1 μas.
- UTLIBR.F - Subroutine to compute the subdiurnal librations in UT1.
- FUNDARG.F - Subroutine to compute the lunisolar fundamental arguments.
- FCNNUT.F - Computes corrections to the coordinates of the CIP to account for Free Core Nutation. Contains data table to be updated each year.  (Updated 10 August 2012)
- Table 5.2a - IAU 2006/2000A expression of the X coordinate of the CIP in the GCRS.
- Table 5.2b - IAU 2006/2000A expression of the Y coordinate of the CIP in the GCRS.
- Table 5.2d - IAU 2006/2000A expression of the quantity s(t) + XY/2.
- Table 5.2e - IAU 2006/2000A expression for Greenwich Sidereal Time GST.
- Table 5.2f - Expression for the difference between the IAU 2006 (or IAU 2000A_R06) and IAU 2000 expression for various quantities (X, Y, Dpsi, Deps, s+XY/2).
- Table 5.3a - Nutation in longitude (IAU 2000_R06 expression) derived from the IAU 2000A lunisolar and planetary components with slight IAU 2006 adjustments.
- Table 5.3b - Nutation in obliquity (IAU 2000_R06 expression) derived from the IAU 2000A lunisolar and planetary components with slight IAU 2006 adjustments.
 Provided by A. Brzezinski.
 From the model by Simon et al. (1994).
 Provided by S. Lambert
 Provided by N. Capitaine