From jim.ray at noaa.gov Tue Mar 18 10:07:15 2008 From: jim.ray at noaa.gov (Jim.Ray) Date: Tue, 18 Mar 2008 13:07:15 -0400 Subject: [IGSMAIL-5738]: ILRS tracking of PRN05 & 06 Message-ID: <47DFF6C3.9070909@noaa.gov> ****************************************************************************** IGS Electronic Mail 18 Mar 10:07:21 PDT 2008 Message Number 5738 ****************************************************************************** Author: Mike Pearlman (forward by Jim Ray) ******************************************************************************** SLR Electronic Mail Tue Mar 18 17:46:58 CET 2008 Message No. 1650 ******************************************************************************** Author: Mike Pearlman Subject: GPS-35 and -36 Tracking Campaign Dear Colleagues: The GPS-35 and -36 satellites will soon be decommissioned. They will continue to operate for a while, but they will not be used in the GPS navigation complex. These are the only GPS satellites that have retroreflectors and this may be our last chance to acquire a good set of GPS data for long term studies, system comparisons, and reference frame support. The ILRS Governing Board has approved an intensive tracking campaign on GPS-35 and -36 running from March 25 through May 31. The priority on GPS-35 and -36 will be raised to follow the Lageos Satellites. Pass segments should be 15 minutes (3 normal points) with 3 segments spread out over the pass to the extent possible. Viewing schedules show that nighttime passes will be visible for GPS- 35 in Europe, Saudi Arabia, South Africa, Eastern Australia, Tahiti and the Western US during this period. Nighttime passes for GPS-36 should be visible from Asia, South America, Australia and Eastern US. If you think you can get any daylight data, please try. It would certainly be very helpful, but don't spend too much time on it. The GPS Satellites are challenging targets, but it is very important to do the best we can to provide an SLR data set that will be available for future analysis. If you have any questions, please contact me. Good luck, Mike Pearlman Director ILRS Central Bureau Dr. Michael R. Pearlman Harvard-Smithsonian Center for Astrophysics 60 Garden St. Cambridge MA 02138 tel. (617) 495-7481 fax. (617) 496-0121 e-mail. mpearlman at cfa.harvard.edu From: "Mike Pearlman" ********************************************************************************