Re: photometric vs. non-photometric

[Jure Skvarc <jure.skvarc@ijs.si>]

>   Open question to the TASS mailing list: given a stream of data,
> night after night, of stellar positions with some estimated
> uncertainty "sigma" arcseconds, how should we identify detections
> as instances of the same physical object?  Perhaps we should wait
> until N nights have been collected and then merge all at once,
> rather than merging 1 night at a time in a gradual process?
> 

It would be useful to match all detected objects to a catalog such as
USNO A2.0 or Guide 1.1.  Positions there are rather good in comparison
to TASS astrometric accuracy and both catalogs go deeper than MARK
III.  So, as the star coordinate you can keep the catalog coordinate,
or better, it can be retrieved from the catalog using a cross-ID
field.  Non-star objects, such as asteroids and galaxies can also be
identified and either flagged in some way or removed from the
database.  The remaining objects can be treated in the same way as now
with additional cleaning procedure which would merge possible close
pairs which actually represent a single object.  This should be run
periodically, every month or so.  Such non-moatched objects are also
good candidates for further inspection.


				regards,
					Jure Skvarc