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SUBPROGRAM SPECIFICATIONS
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SLA_ECLEQ - Ecliptic to Equatorial
SLA_ECMAT - Form
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
v
ecl
=
M
v
equ
.
2.
The equator, equinox and ecliptic are mean of date.
REFERENCE:
Murray, C.A.,
Vectorial Astrometry
, section 4.3.
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SUBPROGRAM SPECIFICATIONS
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SLA_ECLEQ - Ecliptic to Equatorial
SLALIB --- Positional Astronomy Library
Starlink User Note 67
P. T. Wallace
25 January 2000
E-mail:ptw@star.rl.ac.uk