We would like to announce a further pre-release of a
standard for the exchange of optical (visible/IR) interferometry data.
Earlier versions of this standard were presented and discussed at the
2001 and 2002 meetings of the IAU Working Group on Optical/IR
Interferometry.  The latest draft addresses some minor issues
uncovered by John Monnier in updating his IDL reader/writer code for
the previous release of the standard.

The specification of the OI_TARGET table has been changed in the
latest release. The apparent RA and Dec have been removed (since the
epoch for these positions is potentially ambiguous).  The columns for
the (RA, Dec) at the mean equinox have been renamed to RAEP0 and
DECEP0 (to match the column names from the FITS-IDI standard), and
RA_ERR and DEC_ERR are now the uncertainties in RAEP0 and DECEP0.

The following material is available at the webpage
http://www.mrao.cam.ac.uk/~jsy1001/exchange/

* Release 4 of the format specification

* Release 3 of the example C code (compatible with the latest format
  specification)

* Link to v0.1 of John Monnier's IDL code (compatible with the
  latest format specification)

We would like to propose freezing the specification on 1st April
2003. This means changing the revision numbers (OI_REVN) of the tables
to unity. Further enhancements to the standard are not precluded by this,
but will require increments of the revision numbers of any changed
tables.

Comments on this proposal, and suggestions for changes to the standard
should be addressed to the oi-data email exploder at
oi-data@rsd.nrl.navy.mil
 
John Young (COAST), Tom Pauls (NPOI), and John Monnier (Univ. Michigan)