SLA_ECMAT

Form α, δ λ, β 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 (JD2400000.5)


RETURNED:

RMAT

D(3,3)

rotation matrix


NOTES:
(1)
RMAT is matrix M in the expression vecl = Mvequ.
(2)
The equator, equinox and ecliptic are mean of date.
REFERENCE:
Murray, C.A., Vectorial Astrometry, section 4.3.