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SLA_ECMAT - Form $\alpha,\delta\rightarrow\lambda,\beta$ Matrix

ACTION:
Form the equatorial to ecliptic rotation matrix (IAU 1980 theory).
CALL:
CALL sla_ECMAT (DATE, RMAT)

GIVEN:

DATE D TDB (formerly ET) as Modified Julian Date (JD-2400000.5)

RETURNED:

RMAT D(3,3) rotation matrix

NOTES:
1.
RMAT is matrix M in the expression vecl = M$\cdot$vequ.
2.
The equator, equinox and ecliptic are mean of date.

REFERENCE:
Murray, C.A., Vectorial Astrometry, section 4.3.


next up previous
Next: SLA_ECOR - RV & Time Corrns to Sun
Up: SUBPROGRAM SPECIFICATIONS
Previous: SLA_ECLEQ - Ecliptic to Equatorial

SLALIB --- Positional Astronomy Library
Starlink User Note 67
P. T. Wallace
12 October 1999
E-mail:ptw@star.rl.ac.uk