[DORISMail] No 0354 : new DORIS IGN/JPL cumulative solutions (IGN04D01 and IGN04D02) available at CDDIS Dear colleagues, The IDS IGN/JPL Analysis Center has just computed 2 new cumulative solutions (positions and velocities estimated over the whole 1993/1/1-2004/9/22 period): ftp://cddisa.gsfc.nasa.gov/pub/doris/products/sinex_global/ign/ign04d01.snx.Z IGN04D01 = free-network solution. No local tie added. This is the solution for reference frame experts who want to combine it with external information (results from other technique, other local tie information, a priori velocity constraints,...) (superseeds IGN03D01 computed with the same strategy but with less DORIS data) ftp://cddisa.gsfc.nasa.gov/pub/doris/products/sinex_global/ign/ign04d02.snx.Z IGN04D02 = Local tie information used. Projected and transformed into ITRF2000. This is the solution for people who want a position and/or a velocity directly expressed in ITRF2000. (superseeds IGN03D02 computed with the same strategy but with less DORIS data) Starting with the next submission (week 1287 = 04249), all IGN/JPL products will use this improved reference. The geocenter and the EOP time series will be totally recomputed using this new reference. For those interested, you will see that the differences are extremely small except for standard deviations of recent data (basically after 2004.0), this is due to the fact that IGN04D02 has more new DORIS stations in it (all present stations in fact, while the previous reference had 1 year of data less) and to some less precise velocities in the past submission as there was less data available. We have also used recent DORIS-DORIS local tie information as provided recently by Herve Fagard (IGN/SIMB). For all these reasons, the 7-parameter transformation is more robust after 2004.0. There is then no need to use a different name for these products. However, it will help us provide more reliable results within the next year or so before the next realization based on ITRF2004 this time. We do not plan to resubmit the entire ignwd04 time series (transformed into ITRF2000) as the differences are very minimum. However, these solutions have been computed at JPL and the only things presently missing is the sinex conversion itself and the transfer procedure to CDDIS. If somebody would be really interested we could provide it too. The ignwd05 time series (used for the IERS Combination Pilot Project) was not changed as the reference is not used at all in the free-network solution. Documentation has been updated. In particular, more information as available concerning the compensation (chi2/dof) as well as the data really used (number of weeks, start and end time). We also added more comprehensive information concerning breaks that we used in the time series as well as data we had to delete to compute these cumulatives solutions ftp://cddisa.gsfc.nasa.gov/pub/doris/products/sinex_global/ign.snx.readme ftp://cddisa.gsfc.nasa.gov/pub/doris/products/sinex_global/ign/ign04d01.snx.dsc ftp://cddisa.gsfc.nasa.gov/pub/doris/products/sinex_global/ign/ign04d02.snx.dsc Please feel free to recontact us if you would like to have more information or if you have some suggestions on these products. Best regards Pascal -- Pascal Willis Jet Propulsion Laboratory, MS 238-646 Ph : 1-818-393-4748 4800 Oak Grove Drive FAX: 1-818-393-4965 Pasadena CA 91109 Em : Pascal.R.Willis@jpl.nasa.gov