Subject: [SLR-Mail] No. 899: Preparations for GRACE launch From: Ch. Reigber, R. König, R. schmidt, GFZ Potsdam > ******************************************************************************** SLR Electronic Mail 2002-02-19 09:27:00 UTC Message No. 899 ******************************************************************************** Author: Ch. Reigber, R. König, R. schmidt, GFZ Potsdam Subject: Preparations for GRACE launch Dear colleagues, the launch of the GRACE satellites is presently scheduled for March, 16th 2002. GFZ will routinely provide the standard orbit prediction products for the support of the ILRS ground station network. Please note the following specifications: o The heading satellite is labelled GRACE-A, the trailing satellite is labelled GRACE-B. o GFZ will generate and disseminate individual product sets for each of the two GRACE satellites. o GFZ will generate the following products for each GRACE satellite: Tuned InterRangeVectors (IRVs) Adjacent drag functions (DRAG) SAO elements (SAO) Twoline elements (TLE) o GFZ product sets will be disseminated to the following (standard) recipients: - GFZ ftp server at Potsdam - ILRS data centers at CDDIS and EDC - ILRS stations through ´ilrspred@ilrs.gsfc.nasa.gov´ mail-exploder - ILRS stations through GFZ mail-exploder (identical to the mail- exploder at GFZ used for CHAMP) At the ftp sites all product types (IRVs, DRAG, SAO and TLE) will be stored. The standard products sent by email are the IRVs and the DRAG files. o The mail-subjects will read, e.g. for GRACE-A: - IRVs: ”GRACE-A SUBDAILY IRVS GFZ” - DRAG: ”GRACE-A FR drag function” (- SAO: ”GRACE-A SUBDAILY SAO GFZ”) (- TLE: ”GRACE-A SUBDAILY TLE GFZ”) For GRACE-B the satellite name is changed accordingly. o The following satellites numbers will be used: | satellite number | Product -----------+------------------------------+------------- GRACE-A | 0299901 COSPAR (preliminary) | SAO, TLE | 8003 SIC (fixed) | IRVs, DRAG -----------+------------------------------+------------- GRACE-B | 0299902 COPSAR (preliminary) | SAO, TLE | 8004 SIC (fixed) | IRVs, DRAG -----------+------------------------------+------------- The preliminary COSPAR numbers should be used by ILRS stations in their NPs data files. o As soon as the onboard GPS navigation solution from the satellites´ receiver is routinely available, GFZ predictions will be based on this data type and available SLR tracking data. The planned update rate of the predictions is 2-3 products/per day/per satellite. o A preliminary set of products for GRACE-A and GRACE-B based on the nominal separation information will be distributed within the next days (i.e. week 8, 2002). General information on the mission can be found at the following web-sites http://www.csr.utexas.edu/grace http://op.gfz-potsdam.de/grace/index_GRACE.html Best regards, Chris Reigber GRACE mission Co-PI Rolf König LTS manager Roland Schmidt From: Roland Schmidt ********************************************************************************