From AC Thu Sep 15 12:44:29 1994 From: AC (AC) Date: Thu, 15 Sep 1994 12:44:29 PDT Subject: [IGSMAIL-0731] Wk 0755-759 IGS Final Orbits Message-ID: ****************************************************************************** IGS Electronic Mail Thu Sep 15 12:44:29 PDT 1994 Message Number 0731 ****************************************************************************** Author: AC Coordinator Subject: Wk 0755-759 IGS Final Orbits ******************************************************************************* IGS Final orbits/clocks completed and put onto CDDIS (Weeks 755 -759) (June 26 - July 30, 1994) ******************************************************************************* According to the recommendations of the Analysis Centre Workshop the IGS Rapid Orbits were recomputed using up to date orbits and the final EOP values of Bulletin B, published by IERS. ( Daily values, page 2 of Bull. B ) The EOP were corrected for the difference between the IERS pole series and ITRF as published in the IERS 1992 Annual Report (p. II-17, Table II-3), so both the IGS orbits and the associated ERP files are consistent with ITRF92 (current epoch). We have downloaded all the submitted ephemeris and ERP files from CDDIS before the final orbit/clock combination to ensure that the sets are complete and up to date. In the final combination we have largely followed the actions taken during the Rapid orbit generation and since there were very few orbit resubmissions, both the IGS Rapid and Final orbits are virtually same except for the the orientation difference (the current Bull.A and final Bull.B). Orbit evaluation are also nearly the same, since we used centre specific ERP in the long arc evaluations. For more information see the corresponding summary files on CDDIS. Starting with the GPS week 742 a new clock combination scheme was put in place for the final orbit/clock combinations. The clock solution alignment and centre clock weight assignment are based on non SA broadcast satellite corrections only (PRN12, 15, 20). This should result in more realistic and objective clock weighting than employed before, provided that the non SA satellites are representatives of centre clock solution quality. Starting with the GPS week 756 the new IGS erp format (see IGSMAIL# 662) is used by all Analysis Centres and for the IGS erp files. ERP rates, whenever given, are also utilized in both orbit combination and the long arc evaluation. PRODUCTS GENERATED: The resulting final IGS ephemeris and clocks are in daily files in the SP3 format. The sat. orb. accuracy codes displayed in the headers are based on weighted RMS for each satellite. Note that each file contains all the submitted satellites. If satellite or centre had to be excluded from the combination it is noted in the summary file along with the reason for doing so. The IGS FINAL ORBIT files generated and uploaded into CDDIS @ NASA/GSFC are: IGS07550-6.SP3 IGS GPS orbit/clock files for days 0-6, week 0755 IGS07560-6.SP3 IGS GPS orbit/clock files for days 0-6, week 0756 IGS07570-6.SP3 IGS GPS orbit/clock files for days 0-6, week 0757 IGS07580-6.SP3 IGS GPS orbit/clock files for days 0-6, week 0758 IGS07590-6.SP3 IGS GPS orbit/clock files for days 0-6, week 0759 IGS07557.ERP EOP associated with the above orbits (Bull. B aligned to ITRF) IGS07567.ERP EOP associated with the above orbits (Bull. B aligned to ITRF) IGS07577.ERP EOP associated with the above orbits (Bull. B aligned to ITRF) IGS07587.ERP EOP associated with the above orbits (Bull. B aligned to ITRF) IGS07597.ERP EOP associated with the above orbits (Bull. B aligned to ITRF) IGS07557.SUM Complete summary/statistics report IGS07567.SUM Complete summary/statistics report IGS07577.SUM Complete summary/statistics report IGS07587.SUM Complete summary/statistics report IGS07597.SUM Complete summary/statistics report The old Rapid Orbit files have been renamed (on CDDIS) to: (Note this is temporary, based on discussions with AC and GB and may be changed ) IGR07550-6.SP3 Rapid service orbits/clocks for days 0-6, week 755 IGR07560-6.SP3 Rapid service orbits/clocks for days 0-6, week 756 IGR07570-6.SP3 Rapid service orbits/clocks for days 0-6, week 757 IGR07580-6.SP3 Rapid service orbits/clocks for days 0-6, week 758 IGR07590-6.SP3 Rapid service orbits/clocks for days 0-6, week 759 IGR07557.ERP Rapid service EOP associated with the above orbits (Bull A) IGR07567.ERP Rapid service EOP associated with the above orbits (Bull A) IGR07577.ERP Rapid service EOP associated with the above orbits (Bull A) IGR07587.ERP Rapid service EOP associated with the above orbits (Bull A) IGR07597.ERP Rapid service EOP associated with the above orbits (Bull A) IGR07557.SUM Rapid service complete summary/statistic report IGR07567.SUM Rapid service complete summary/statistic report IGR07577.SUM Rapid service complete summary/statistic report IGR07587.SUM Rapid service complete summary/statistic report IGR07597.SUM Rapid service complete summary/statistic report ***************************************************************************** REMARKS/CORRECTIONS: None [Mailed From: Jan Kouba ]