EME2000 orientation used at several places where ICRF orientation should be used
There are several places where EME2000 orientation is used when ICRF orientation should be used.
The first example concern the definition of ICRF itself, which was aligned with EME2000.
Initial investigations showed that this was in fact a consequence of a
wrong implementation of the dummy
IAU pole used for the dummy celestial bodies representing solar system barycenter and Earth-Moon barycenter.
Further investigations showed that in fact all IAU poles were not
used correctly in the
JPLCelestialBody.InertiallyOriented internal class.
The orientation error corresponds to the forgotten bias between EME2000
and GCRF, as ICRF and GCRF are aligned
with each other. The main effect of this error is that the Sun direction which is used in many places in Orekit
(eclipse computation, solar radiation pressure, Sun pointed attitude ...) is slightly wrong, to the level of a
few tens of milli-arcseconds.
(from redmine: issue id 130, created on 2013-03-27, closed on 2013-03-27)