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Diffstat (limited to 'src/slalib/nut.f')
-rw-r--r-- | src/slalib/nut.f | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/src/slalib/nut.f b/src/slalib/nut.f new file mode 100644 index 0000000..bf2d196 --- /dev/null +++ b/src/slalib/nut.f @@ -0,0 +1,44 @@ + SUBROUTINE sla_NUT (DATE, RMATN) +*+ +* - - - - +* N U T +* - - - - +* +* Form the matrix of nutation for a given date - IAU 1980 theory +* (double precision) +* +* References: +* Final report of the IAU Working Group on Nutation, +* chairman P.K.Seidelmann, 1980. +* Kaplan,G.H., 1981, USNO circular no. 163, pA3-6. +* +* Given: +* DATE dp TDB (loosely ET) as Modified Julian Date +* (=JD-2400000.5) +* Returned: +* RMATN dp(3,3) nutation matrix +* +* The matrix is in the sense V(true) = RMATN * V(mean) +* +* Called: sla_NUTC, sla_DEULER +* +* P.T.Wallace Starlink 1 January 1993 +* +* Copyright (C) 1995 Rutherford Appleton Laboratory +*- + + IMPLICIT NONE + + DOUBLE PRECISION DATE,RMATN(3,3) + + DOUBLE PRECISION DPSI,DEPS,EPS0 + + + +* Nutation components and mean obliquity + CALL sla_NUTC(DATE,DPSI,DEPS,EPS0) + +* Rotation matrix + CALL sla_DEULER('XZX',EPS0,-DPSI,-(EPS0+DEPS),RMATN) + + END |