format at CDDIS Dear Colleagues, As you all know, the three recently launched satellites, i.e. JASON-1, ENVISAT and SPOT-5 are fitted out with a second generation DORIS receiver. One of the new features of this receiver is the dual-channel, enabling to perform simultaneous measurements from two ground stations. It was thus necessary to slightly adapt the existing DORIS Data Exchange format in order to take this feature into account (revision 2.1) : <> In fact this format is very similar to the existing one, but some fields have a different meaning: - columns 46-56: Range rate is computed with f(bea)= nominal (instead of best estimate) beacon frequency - columns 90: Channel indicator Users should also look at the column 35: preprocessing indicator Until now, CNES only delivered measurements considered to be good (value = 0) and it was not necessary to pay attention to this indicator. Now CNES may also deliver edited measurements (value=1 for preprocessing, value=2 for postprocessing) The topic was discussed during the Analysis Workshop held in June in Biarritz (see the report available on http://lareg.ensg.ign.fr/IDS/events/cr_biarritz.html). The IDS Steering Committee decided that Observational data from all DORIS satellites starting from January 15, 2002 should be delivered to the IDS Data Centers in the 2.1 format after tests by the Analysis Centers. In order to allow you to perform these tests, DORIS measurements using this format are now available at the CDDIS Data Center, starting with: - cycle 344 for TOPEX/POSEIDON (15 to 24 Jan 2002) - arc 413 for SPOT-2 (11 to 17 Jan 2002) - arc 168 for SPOT-4 (11 to 20 Jan 2002) - cycle 1 for JASON-1 (15 to 24 Jan 2002) Files using the new 2.1 format have a new_ prefix (also used for replacement files for early TOPEX files using the old format) Note: Information about how to process these data is included in the format description. A new DORIS Mail will provide complementary information, if necessary. SPOT-5 measurements should also be available very soon, using the same format. Best regards, Carey Noll IDS Data Flow coordinator and CDDIS Data Center Gilles Tavernier IDS Central Bureau 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 _____________________________________________________ [ Part 2, Text/PLAIN (Name: "doris.format.rev5.txt") 168 lines. ] [ Unable to print this part. ] [ Part 3: "Attached Text" ] Please do not reply directly to this message, but send comments and suggestions to IDS.central.bureau@cls.fr