Hi Luc,
On Thu, 2017-04-20 at 16:44 +0200, Luc Maisonobe wrote:
Le 20/04/2017 à 16:22, Ward, Evan a écrit :
Hi All,
Hi Evan,
I noticed that LocalOrbitalFrame is deprecated now. Is there a planned
replacement? I think LOF is useful for studying relative motion,
especially comparing one ephemeris for a satellite with another. The
LOF frame transformation causing propagation is not a problem in this
use case because the propagation is just interpolating an ephemeris.
The comment on LOF suggests using SpacecraftState.toTransform() but
that would be based on the satellite's attitude instead of the local
orbital frame.
I understand your concern. I am not really happy with the implications,
but I understand this.
If you think Orekit is better off without the LOF class I can copy
the source to my local projects.
Perhaps we could remove the deprecation but put a big warning about
a full propagation being triggered each time getTransformTo is called.
I fear someone will use this for formation flying, with one spacecraft
being defined relative to the other and thousands of propagation being
run.
I agree this would be bad using a NumericalPropagator since the
integrator would never really get started.
So go ahead with removing the deprecation, with proper documentation.
OK. Would it be OK to just throw a UnsupportedOperationException in
the FieldTransform method if the LOF is built with a Propagator? I
can add a separate constructor for a FieldPropagator so the
FieldTransform will work.