SLA_RVEROT

RV Corrn to Earth Centre

ACTION:
Velocity component in a given direction due to Earth rotation.
CALL:
R = sla_RVEROT (PHI, RA, DA, ST)
GIVEN:

PHI

R

geodetic latitude of observing station (radians)

RA,DA

R

apparent [α, δ] (radians)

ST

R

local apparent sidereal time (radians)


RETURNED:

sla_RVEROT

R

Component of Earth rotation in direction [RA,DA] (km s1)


NOTES:
(1)
Sign convention: the result is positive when the observatory is receding from the given point on the sky.
(2)
Accuracy: the simple algorithm used assumes a spherical Earth and an observing station at sea level; for actual observing sites, the error is unlikely to be greater than 0.0005 km s1. For applications requiring greater accuracy, use the routine sla_PVOBS.