THIS SUBROUTINE NUTATES EQUATORIAL RECTANGULAR COORDINATES FROM
THE MEAN DYNAMICAL EQUATOR AND EQUINOX OF EPOCH TO THE TRUE
EQUATOR AND EQUINOX OF EPOCH. SEE EXPLANATORY SUPPLEMENT TO THE
ASTRONOMICAL ALMANAC, PP. 114-115.
TJD = TDB JULIAN DATE OF EPOCH (IN)
POS1 = POSITION VECTOR, GEOCENTRIC EQUATORIAL RECTANGULAR
COORDINATES, REFERRED TO MEAN DYNAMICAL EQUATOR AND
EQUINOX OF EPOCH (IN)
POS2 = POSITION VECTOR, GEOCENTRIC EQUATORIAL RECTANGULAR
COORDINATES, REFERRED TO TRUE EQUATOR AND EQUINOX
OF EPOCH (OUT)
NOTE: IF TJD IS NEGATIVE, INVERSE NUTATION (TRUE TO MEAN)
IS APPLIED.
Nodes of different colours represent the following:
Solid arrows point from a procedure to one which it calls. Dashed
arrows point from an interface to procedures which implement that interface.
This could include the module procedures in a generic interface or the
implementation in a submodule of an interface in a parent module.
Nodes of different colours represent the following:
Solid arrows point from a procedure to one which it calls. Dashed
arrows point from an interface to procedures which implement that interface.
This could include the module procedures in a generic interface or the
implementation in a submodule of an interface in a parent module.