SLA_MOON

Approx Moon Pos/Vel

ACTION:: Approximate geocentric position and velocity of the Moon (single precision).
CALL:: CALL sla_MOON (IY, ID, FD, PV)

PV	R(6)	Moon $[x, y, z, ẋ, ẏ, ż]$ , mean equator and equinox of date (AU, AU s $^{- 1}$ )

NOTES:

(1): The date and time is TDB (loosely ET) in a Julian calendar which has been aligned to the ordinary Gregorian calendar for the interval 1900 March 1 to 2100 February 28. The year and day can be obtained by calling sla_CALYD or sla_CLYD.
(2): The position is accurate to better than 0.5 arcminute in direction and 1000 km in distance. The velocity is accurate to better than ′′05 per hour in direction and 4 metres per second in distance. (RMS figures with respect to JPL DE200 for the interval 1960-2025 are $14$ $^{'}^{'}$ and ′′02 per hour in longitude, $9$ $^{'}^{'}$ and ′′02 per hour in latitude, 350 km and 2 metres per second in distance.) Note that the distance accuracy is comparatively poor because this routine is principally intended for computing topocentric direction.
(3): This routine is only a partial implementation of the original Meeus algorithm (reference below), which offers 4 times the accuracy in direction and 20 times the accuracy in distance when fully implemented (as it is in sla_DMOON).