> Okay, I'd like to bring up my current pet peeve about the NVO cone search
> standard (ie http://www.us-vo.org/metadata/conesearch/), which is that it
> doesn't include either equinox or epoch.
Let me add my take (as an astrophysicist) on this.
- Epoch. If you change the epoch of a cone search the answer should
change, that's because some high proper motion objects will move through
the cone with time. So, a database with proper motions should accept and
use an epoch. A database without proper motions should return what epoch
the data refer to. Without this, cetrain science programmes will be
impossible (e.g. proper motion studies).
- Equinox really should be dealt with, and dealt with properly. Its all
very well to say "everything in the VO will be equinox 2000", but it seems
to me to be building in a serious limitation at an early stage. Folks
should be making the data available in what ever equinox is needed, and
then it should be converted (on the fly?) to what the user wants. If not,
how are we going to cope if there is another change such as that from
Besselian to Julian equinoxes?
Tim
--
-----------------------------------------------------------------------------
Prof. Tim Naylor,
School of Physics,
University of Exeter,
Stocker Road,
Exeter
EX4 4QL
E-mail: T.Naylor-at-exeter.ac.uk
tel: 01392 264172
-----------------------------------------------------------------------------
Received on 2003-09-22Z20:01:52