SLA_PRENUT

Precession-Nutation Matrix

ACTION:

Form the matrix of precession and nutation (SF2001).

CALL:

CALL sla_PRENUT (EPOCH, DATE, RMATPN)

GIVEN:

RETURNED:

NOTES:

(1)

The epoch and date are TDB. TT (or even UTC) will do.

(2)

The matrix is in the sense:

v${}_{true}$ = M$\cdot$v${}_{mean}$

where v${}_{true}$ is the star vector relative to the true equator and equinox of epoch DATE, M is the $3\times 3$ matrix RMATPN and v${}_{mean}$ is the star vector relative to the mean equator and equinox of epoch EPOCH.