Date: Tue, 09 Apr 2002 11:06:22 +0200
From: Jean-Jacques Valette <valette@cls.fr>
To: jean-paul.berthias@cnes.fr, Pascal Willis <Pascal.R.Willis@jpl.nasa.gov>
Cc: ries@sol.csr.utexas.edu, bjh@cobra.jpl.nasa.gov, feissel@ensg.ign.fr,
    Carey Noll <carey.noll@gsfc.nasa.gov>, frank.lemoine@gsfc.nasa.gov,
    nerem@colorado.edu, nzelensk@geodesy.gsfc.nasa.gov,
    krchoi@csr.utexas.edu, "Tavernier, Gilles" <Gilles.Tavernier@cnes.fr>,
    yeb@cobra.jpl.nasa.gov, Christian Jayles <christian.jayles@cnes.fr>,
    werner.gurtner@aiub.unibe.ch,
    Jean-Jacques Valette <jvalette@priam.cls.fr>,
    "Granier, Jean-Pierre" <Jean-Pierre.Granier@cnes.fr>,
    Alfred Piuzzi <alfred.piuzzi@cnes.fr>,
    Sabine Houry <sabine.houry@cnes.fr>,
    Flavien Mercier <flavien.mercier@cnes.fr>,
    beatrice Nhun Fat <nhunfat@cls.fr>, laurent.soudarin@cls.fr
Subject: Re: Please change DORIS/SPOT preprocessing and DORIS/CDDIS  files

Dear colleagues,

Concerning the DORIS data to be provided to IDS users, I agree with 
Jean-Paul : it is not only a question of format. My feeling is that no 
constructive discussion is possible until the analysists will have 
experiment "raw data" (no corrections of time tags and Dopplers, aditionnal 
400 MHz data).

I would recommend to adopt June 2001 as a test period and to generate an 
extended (and temporary) 2.1 CDDIS format. That period is the one choozen 
for the Analysis Campaign. Preliminary results (time tags, clock drifts, 
residuals, bias, if available geodetic products) may be discussed at 
Biarritz and will help to define the final 3.0 format.

Of course, this wish is probably not realistic if we consider that SOD/CNES 
team is very busy with Jason and Envisat recent launches and Spot5 to come. 
So, why not having a look at any other complementary ressources? For 
example at SSALTO where the DORIS ground segment collects and routinely 
preprocesses data (continuous time tags comparisons are made with the 
SOD/POD one's). Perhaps Gilles could tell us if anything can be done on 
that way? It is clear that such a work should be done with a close 
collaboration with JPB and any other actors.

Jean-Jacques

PS : for those who can speak french, the following reference gives the 
DORIS time tags spec. As far as I known, there is no english version. 
"Spécifications techniques de la datation du système DORIS". J. Noubel 
CNES, 10/12/2001