Dear Colleagues,

as additional information relevant for the IERS CPP I would like
to inform you about the issues discussed at the IERS
Directing Board Meeting on September 23, 2004, in Paris.

At this IERS DB Meeting two proposals were presented
concerning long time series of "weekly" SINEX files:

1) ITRF2004 (Boucher): to generate a new ITRF solution long time
   series of "weekly" SINEX solutions are required.
2) IERS2005 (Rothacher): to extend the IERS Combination Pilot
   Project (CPP) into the past and to generate a first set of
   combined solutions of ITRF+EOP(+ICRF), long time series of
   "weekly" SINEX solutions are required as well.

The short presentation I gave about the IERS2005 project is
given as attachment to this e-mail.

It was decided that the two calls for long time series should
be combined into one coordinated call, because it does not make
sense at all to have two calls for exactly the same time series.
The series can be used for both projects.

Claude Boucher and myself agreed at the meeting, that we will coordinate
the issue and that he will write a first draft to be modified by me and
other parties involved.

The call for participation has been prepared and will be distributed
as soon as the text has been finalized (this or next week).

The call will ask for long time series of "weekly" SINEX files from
the Technique Services or, in special cases (longer series, more homogeneous
modelling, etc.) from individual analysis centers, if approved by the
corresponding Technique Service.

At the IERS DB Meeting the issue of including the ICRF into an IERS2005
project was considered and critically discussed. It was stated, that the
long term goal should indeed be to include the ICRF as well, but that the
term ICRF2005 should not be used at the moment, because it might
cause confusion in the astronomical community. Therefore and also because
quasar coordinates might not be available in SINEX files in due time, we
should see the realization of an IERS200x (with consistent ITRF200x, EOP200x
and ICRF200x) as a future goal and at the moment concentrate on the two
pillars "ITRF" and "EOPs".

With best regards,
                                Markus