The International DORIS Service (IDS) workshop was held on November 12-14, 2008. The purpose of this workshop was to get representatives from all IDS groups together to share information about the network, data, products, developments and results in all aspects of DORIS. The meeting was a platform for discussion and coordination of future activities.
Along with this workshop, two related events took place in the same week, the annual meeting of the Ocean Surface Topography Science Team (OSTST) and the final symposium of Global Ocean Data Assimilation Experiments (GODAE). These three events were held on 10 to 15 of November 2006, in Nice, France.

The oral and poster presentations of the OSTST meeting are available on the AVISO Website

The presentations of the IDS Workshop can be found hereafter.

Workshop Summary

IDS Analysis Centers / IDS contribution to ITRF2008
Seven DORIS analysis centers participated in the workshop, including four official analysis centers (IGN; LCA or CNES/CLS; GOP or Geodetic Observatory Pecny; ESA or European Space Operations Center), and three candidate analysis centers (UNC - University of Newcastle; GAU - Geoscience Australia; and GSC - NASA Goddard Space Flight Center). All these centers have agreed to provide SINEX solutions for inclusion in the IDS combined solution that will be submitted to the IERS for ITRF2008. In addition, INA, Institute of Astronomy, Russian Academy of Sciences, will also submit a SINEX solution for the DORIS combination. For ITRF2005, only two individual DORIS solutions were included: IGN and LCA.

Future missions
The maintenance of the DORIS constellation with at least four DORIS satellites is now planned at least through 2019. Future missions that will carry a DORIS receiver include Cryosat-2 (ESA cryosphere mission, launch 2009), Altika (ISRO/CNES ocean altimetry mission, launch 2010), HY2A (CSA/CNES ocean altimetry mission, launch 2010), SENTINEL-3 (ESA observation platforms, launch 2012).

Jason-2/DGXX generation instrument
The Jason-2 DGXX receiver can track DORIS beacons with as many as seven channels, permitting many more instances of simultaneous observations. The spacecraft carries the high-performance on-board real-time DIODE orbit navigator. The DORIS data are furnished in form of phase measurements in a new GPS-like RINEX format. Precise orbit determination (POD) results obtained with Jason-2 indicate the receiver on Jason-2 is operating within specifications, producing 1-2 cm orbits.

South-Atlantic Anomaly correction
The SAA correction model of H. Capdeville and J.-M. Lemoine will be upgraded based on new information provided by the T2L2 experiment, and radiation monitoring package on Jason-2. The model will need to be adapted when Jason-1 is moved to the interleaved orbit (see next item).

Following an extended discussion at the Ocean Surface Topography Science Team Meeting, the Jason-1 spacecraft (operating in tandem flight mode with Jason-2) will be moved to an interleaved orbit. This means the ground track sampling will interleave with the ground tracks of Jason-2 for purposes of improving the temporal and spatial sampling of oceanographic features with altimetry. The orbit move will likely occur in February 2009.

New DORIS applications
- T2L2 (Time Transfer by Laser Link): time transfer experience on board Jason2 allowing the monitoring of the DORIS USO.
- GRASP (Geodetic Reference Antenna in Space): proposal of a new mission with all the geodetic technics (GNSS, DORIS, VLBI, SLR) collocated on one spacecraft.

Oral and Poster presentations

Wednesday, November 12th, 2008

Session 1 - Doris System
Chairpersons: Franck Lemoine, Gilles Tavernier

DORIS system status and future missions
P. Ferrage, G. Tavernier, A. Auriol
Abstract - PDF slides

DORIS System : the new age
A. Auriol, C. Tourain, B. Besson
Abstract - PDF slides

DORIS / Jason-2 : less than 10cm centimeters orbits soon available for Near-Real-Time Altimetry
C. Jayles, B. Besson, A. Auriol, J.P. Chauveau, F. Rozo
Abstract - PDF slides

DORIS network 2008 status report
H. Fagard
Abstract - PDF slides

Session 2 - Doris System  / IDS organization
Chairpersons: Franck Lemoine, Pascale Ferrage

Impact of ground antennas environment on the on-board received power and Doppler residuals
P. Yaya, H. Fagard, C. Jayles
Abstract - PDF slides

Jason 2 Doris Measurements
F. Mercier, L. Cerri, S. Houry
Abstract - PDF slides

IDS status report
G. Tavernier, H. Fagard, F. Lemoine, C. Noll, R. Noomen, J. Ries, L. Soudarin, P. Willis
Abstract - PDF slides

IDS Inter-Center Analyses and Comparisons for  ITRF2008
F. Lemoine, D. Chinn
Abstract - PDF slides

Thursday, November 13th, 2008

Session 3 - Analysis Centers
Chairpersons: L. Soudarin, P. Willis

Operational IDS combinations in preparation for the next ITRF
J.J. Valette, Z. Altamimi, F. Lemoine, P. Yaya
Abstract - PDF slides

CNES/CLS analysis center  : status report
L. Soudarin, H. Capdeville, J.M. Lemoine, J.F. Crétaux
Abstract - PDF slides

Current Activities of GOP DORIS Analysis Centre
P. Stepanek¸ V. Filler, J. Dousa
Abstract - PDF slides

ESOC IDS (Re-) processing
M. Otten
Abstract - PDF slides

GSFC/NASA Doris contribution to ITRF2008
K. Le Bail, F. Lemoine, D. Chinn
Abstract - PDF slides

Session 4 - Analysis Centers / Geodesy
Chairpersons: M. Otten, P. Stepanek

Towards ITRF2008: Status of DORIS Data Processing at Geoscience Australia
R. Govind, F. Lemoine
Abstract - PDF slides

DORIS Processing at Newcastle University: Contribution to ITRF2008
P. Moore
Abstract - PDF slides

Estimating DORIS drag coefficients: toward an optimum IDS analysis strategy ?
M.L. Gobinddass, P. Willis
Abstract - PDF slides

DORIS weekly station position time series. Status before ITRF2008 analysis
X. Collilieux, Z. Altamimi
Abstract - PDF slides

The Geodetic Reference Antenna in Space (GRASP) Mission Concept
Y. Bar-Server, B. Haines, S. Wu, F. Lemoine, P. Willis
Abstract - PDF slides

Session 5 - Round table: preparation of ITRF2008 and orbit combination activity
Chairpersons: F. Lemoine, JJ Valette
ESOC                                 M. Otten
Geoscience Australia            R. Govind
GOP                                   P. Stepanek
IGN/IPGP                            P. Willis
INASAN                               S. Kuzin
CNES/CLS                          L. Soudarin
NASA/GSFC                        F. Lemoine
IDS Combination center JJ. Valette

Session 6 - Posters
An approach to obtain a tropospheric mapping function based on ECMWF models
L. Soudarin, R. Biancale, S. Dupuy
Abstract - PDF slides

Other posters from OSTST Meeting:

DORIS / Jason-2: less than 10cm centimeters orbits soon available for Near-Real-Time Altimetry
C. Jayles et al.
PDF slides

Doris phase mesurements, rinex format
Flavien Mercier et al.
PDF slides


Friday, November 14th, 2008

Session 7 - Precise Orbit determination / Geophysics atmospheric sciences
Chairpersons: J. Ries, N. Zelinsky

DPOD2005 Performance and Impact of Modelling Improvements for TOPEX, Jason-1, and Jason-2
N. Zelensky, F. Lemoine, D. Chinn, P. Willis, J.P. Boy, D. Rowlands
Abstract - PDF slides

GINS software evolutions for the Jason-2 data processing: RINEX and DORIS 2.2 formats
L. Soudarin, H. Capdeville, J.M. Lemoine, H.M. Pau, B. Nhun Fat
Abstract - PDF slides

Session 8 - New DORIS applications & products
Chairpersons: JJ Valette, K. Le Bail

Time Transfer by Laser Link (T2L2), first results
P. Exertier, E. Samain, P. Guillemot, I. Petitbon, P. Berion O. Laurain, C. Foussard
Abstract - PDF slides

Presentation and discussion :
How to  improve station disturbance detection and warning?
B. Nhun Fat, P. Yaya, H. Capdeville, L. Soudarin, P. Ferrage
PDF slides

Workshop conclusion