| Date: | 1999-01-15 14:41:00 | |
| Sender: | John J. Degnan <> gurtner@ubeclu.unibe.ch (WERNER GURTNER)> | |
| Subject: | [SLR-Mail] No. 216: Extension of the IGEX-98 Campaign: SLR Support | |
| Author: | John J. Degnan | |
| Content: | ******************************************************************************** SLR Electronic Mail 1999-01-15 14:41:00 UTC Message No. 216 ******************************************************************************** Author: John J. Degnan Subject: Extension of the IGEX-98 Campaign: SLR Support id AB08416; Thu, 14 Jan 99 22:49:45 +0100 by ltpmail.gsfc.nasa.gov (8.8.8/8.8.8) with SMTP id QAA16980 for X-Mailer: Windows Eudora Pro Version 3.0 (32) Our SLR liaison with the IGEX-98 campaign, Werner Gurtner, submitted a request to the ILRS Governing Board for three months additional tracking by the SLR network. The ILRS/GB has voted via email to approve this request. All ILRS stations and operations centers are therefore requested to continue the augmented GLONASS tracking support until April 19, 1999. The full text of Werner´s request follows. Please take note that three new GLONASS satellites have been recently launched and more information regarding the possible tracking of one or more of these new satellites will be forthcoming. In the interim, please follow the original tracking priorities for IGEX-98. Sincerely, John J. Degnan Chairperson, ILRS Governing Board >Date: Wed, 13 Jan 1999 09:32:37 +0100 >From: gurtner@ubeclu.unibe.ch (WERNER GURTNER) >To: JJD@ltpmail.gsfc.nasa.gov, JMB@ltpmail.gsfc.nasa.gov, > MPEARLMAN@cfa.harvard.edu, willis@ensg.ign.fr, beutler@aiub.unibe.ch, > gurtner@aiub.unibe.ch, hein@ifen1.bauv.unibw-muenchen.de, > ren@cobra.jpl.nasa.gov, slaterja@acq.osd.mil, noll@cddis.gsfc.nasa.gov >Subject: Extension of the IGEX-98 Campaign: SLR Support >X-VMS-To: DEGNAN_ >X-VMS-Cc: BOSWORTH_,PEARLMAN_,@SYS$LOGIN:IGEX,GURTNER > > >IGEX-98 Steering Committee > > Bern, January 13, 1999 > > Dr. John Degnan > Chairman > International Laser Tracking Network > > >Extension of the SLR support for the IGEX-98 Campaign >***************************************************** > >Dear John, > >the IGEX Steering Committee decided to extend IGEX-98 for an additional >3-month period: The campaign will last until April 19, 1999. (IGEXMail 145, >January 11, 1999). > >There were several good reasons to take this decision: > >- The recent launch of 3 new GLONASS satellites will considerably improve the > satellite constellation and it will enable checking the behaviour of the > satellites in their early life time (out-gassing, etc). > >- Recent installation of additional IGEX receivers lead to a substantial > improvement of the IGEX network, especially in the southern hemisphere > >- Several people expressed their willingness to continue this campaign after >the January 1999 initial deadline. > >During this extra period the Steering Committee will initiate a discussion >about what to do after the formal end of the campaign. A workshop to discuss >analysis results will be held linked to the September 99 ION meeting in >Nashville. > >The Steering Committee is asking the ILRS global network to continue its SLR >tracking support and to extend the tracking to at least one of the recently >launched satellites as soon as they are set healthy. > >The quality of the orbits determined by microwave observations has >substantially increased over the last few weeks. Comparisons of these orbits >with SLR observations seem to show the same 5 cm difference in radial direction >as it has been reported for the two retroreflector-equipped GPS satellites by >the CODE analysis center at the last laser workshop in Deggendorf. The >analysts are eager to confirm this discrepancy and to find out its explanation. > >The extension should also help in deciding to what extent a true combination of >SLR and microwave observations will improve orbit and earth rotation parameter >determination. > >May I ask you to forward this request to the SLR network with an affirmative >recommendation and to designate which one(s) of the new satellites will be >added to the tracking list. > >Thank you very much for your cooperation. > >Sincerely yours > >Werner Gurtner >SLR liaison >IGEX-98 Steering Committee > > > > [Mailed From: John Degnan ******************************************************************************** |