Subject: [DORISMail] No 0219 : Jason DORIS measurements gap ****************************************************************************** DORISMail 07-Feb-2003 11:03:17 Message No 0219 ****************************************************************************** Author: Tavernier Gilles Subject: Jason DORIS measurements gap A new DORIS "flight software" (version 2.08) was up-loaded on-board Jason on November 25, 2002. The instrument was restarted the same day at 12:08. Due to the unavailability of measurements from the Master Beacon of Kourou (ionospheric disturbances on the evening passes), the auto-initialization phase was longer than expected and was completed on November 26, 2002 at 23:20 (UTC). This lead to a gap of 32 hours of DORIS measurements (first measurements around 20:00 on November 26). The main improvement of this new DORIS "flight software" is to allow shifted frequencies for the new third generation DORIS beacons currently being deployed. Today 9 DORIS stations are equipped with such beacons. We successfully tested a shifted frequency beacon installed in Toulouse last week : Jason received and processed the measurements, whereas the nominal frequency master beacon was not affected at all and properly received by all satellites. The same "flight software" update will be applied to ENVISAT end SPOT5 in the next months allowing more flexibility in stations deployment. We apoligize for the late notice. Gilles TAVERNIER _____________________________________________________ CNES DSO/ED/AL/MA - Bpi 2002 Phone : 33 - (0)5 61 27 37 76 18, avenue Edouard Belin Fax : 33 - (0)5 61 28 25 95 31 401 TOULOUSE CEDEX 4 Email : Gilles.Tavernier@cnes.fr _____________________________________________________ Please do not reply directly to this message, but send comments and suggestions to IDS.central.bureau@cls.fr