****************************************************************************** DORISMail 09-Sep-2004 22:03:47 Message No 0345 ****************************************************************************** Author: Pascal Willis Subject: Change in DORIS estimation strategy for ignwd04 and ignwd05 Dear colleagues, for your information, starting with the next processed week (#1281 = 04207) the DORIS weekly sinex solutions ignwd04 (in ITRF2000) and ignwd05 (in free-network) will be processed in a slightly different manner. the ground station wet tropopsheric delays will be estimated per measurement (instead of per pass) using a randomwalk process with a psigma equivalent to 5 cm over 1 day (instead of using white noise resets per pass with a 5 cm per day constraint). Recent results showed here that a 10% improvement could be gained in DORIS EOP accuracy (by comparison to GPS/JPL solution). Impact on station positioning accuracy seem to be minimal. The relevant documentation files (*dsc and *.sum) have also been changed at CCDIS for the IDS and at BKG for IERS. 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 Please do not reply directly to this message, but send comments and suggestions to IDS.central.bureau@cls.fr