| Date: | 2008-06-26 01:12:00 | |
| Sender: | Mike Pearlman ILRS Central Bureau <Mike Pearlman <mpearlman@cfa.harvard.edu>> | |
| Subject: | [SLR-Mail] No. 1688: Jason-2 ... Message to the ILRS Stations | |
| Author: | Mike Pearlman ILRS Central Bureau | |
| Content: | ******************************************************************************** SLR Electronic Mail 2008-06-26 01:12:00 UTC Message No. 1688 ******************************************************************************** Author: Mike Pearlman ILRS Central Bureau Subject: Jason-2 ... Message to the ILRS Stations Subject: Jason-2 Subject: Jason-2 Message to the ILRS Stations: As you know by now, Jason-2 is in orbit and some preliminary SLR data has already been acquired. There was a little confusion over the mislabeling of the predictions, but that has been corrected. When the present maneuvers of Jason-2 are completed by July 3, Jason-2 will follow Jason-1 in tandem orbit by 1 minute in time. This configuration is required for the ocean surface altimeter measurements. SLR tracking is essential for the calibration and validation phase for altimeter and the other on-board systems, and for the operational precision orbit determination. The calibration and validation period will extend from July 12, 2008 through January 2009. The formal tracking program will start on July 4, but the project requests that tracking be initiated as early as possible to check out data flow procedures and to provide some early support for the T2L2 timing experiment (see SLRMAIL 1686). Hopefully most of the maneuvers will be completed by June 30 and tracking will not be too difficult. Since Jason-1 and Jason-2 are at 1350 km; tracking priorities have been set at 7 and 8 respectively, after ERS-2 and before Larets. Occasionally altimeter calibration maneuvers will occur, during which time the spacecraft will not be oriented properly for laser ranging. These lapses will be very short and very infrequent, and they should not affect the predictions. We will try to post notification of these events once the program is underway. The SLR CPF predicts are already generated and available via anonymous ftp at the stations: ftp://cddis.gsfc.nasa.gov/slr/slr/cpf_predicts/2008/jason2/ or ftp://cddis.gsfc.nasa.gov/slr/slr/cpf_predicts/current/ Key parameters for Jason-2 include: COSPAR ID: 0803201 SIC: 1025 NPT Bin size: 15 seconds Center Code for primary prediction provider: cne secondary prediction providers: hts , sgf Once the operational tandem phase begins (July 12), stations are requested to track alternate complete passes of Jason-1 and Jason-2. Stations that can routinely interleave passes, should track each satellites for alternate 2 minute intervals throughout the entire tandem pass. Once you start tracking a tandem pass, do not switch off for another (non-Jason) satellite. Support from the SLR field stations is essential to making this project a success. The Jason Project extends its appreciation for your support. With best regards, Mike From: Mike Pearlman ******************************************************************************** |