| Date: | 1996-06-20 23:00:00 | |
| Sender: | Richard Eanes <[Mailed Richard Eanes <eanes@ramses.csr.utexas.edu>]> | |
| Subject: | [SLR-Mail] No. 20: New Predictions from CSR for L1,L2,ET1,ET2 | |
| Author: | Richard Eanes | |
| Content: | ******************************************************************************** SLR Electronic Mail 1996-06-20 23:00:00 UTC Message No. 20 ******************************************************************************** Author: Richard Eanes Subject: New Predictions from CSR for L1,L2,ET1,ET2 Subject: New Predictions for Lageos-1, Lageos-2, Etalon-1, and Etalon-2: June 1996 through July 1999 New predictions for Lageos-1, Lageos-2, Etalon-1 and Etalon-2 spanning June 1996 through July 1999 have been produced at the University of Texas Center for Space Research. The ephemerides are distributed in the form of daily "tuned IRV`s" suitable for use in the IRVINT tracking software or its derivatives. This is the 27`th ephemeris distributed for Lageos-1 (GSFC ID 1155). For Lageos-2 (GSFC ID 5986) this is the 3`rd ephemeris distributed. For Etalon-1 (GSFC ID 0525) and Etalon-2 (GSFC ID 4146) these are the 8`th ephemerides distributed. Leap seconds have been predicted for the end of June 1997 and the end of June 1999. This prediction is quite uncertain, and should it prove incorrect new tuned IRV`s will be issued. Each of the four IRV files consists of 4624 lines with 293592 bytes. They are available via anonymous ftp at CSR. Use ftp.csr.utexas.edu (129.116.190.30) and cd to pub/slr/ephemeris. The files are lg1irv27_tune, lg2irv03_tune, et1irv08_tune, and et2irv08_tune for Lageos-1, Lageos-2, Etalon-1 and Etalon-2 respectively. They are compressed using the unix command "compress", so the names listed above are followed by .Z in each case. Two other files contain the Earth rotation predictions used in the generation of the IRV`s. The columns in these files are: Modified Julian Date, x and y components of polar motion in arcsec, TAI-UTC and UT1R-TAI in seconds. There is a point every day. The file named irv27_pole_exp was used for Lageos-1 and Lageos-2. The file named irv27et_pole_exp was used for Etalon-1 and Etalon-2. The two Earth orientation files differ only slightly. These files together with up-to-date UT1-TAI values from IERS should be used to derive the UT1 correction for SLR tracking operations. The files will also be made available at the EUROLAS Data Center and at the NASA CDDIS. You can request the files from Wolfgang Seemueller at the EUROLAS Data Center using e-mail address: edc@dgfi.badw-muenchen.de, or from Carey Noll at CDDIS using e-mail address: noll@cddis.gsfc.nasa.gov. I will be glad to respond to any questions about these predictions. I can be reached at e-mail address: eanes@csr.utexas.edu , or by phone at (512)471-7560, or fax at (512)471-3570. --------------------------------------------------------------------------- Richard Eanes, eanes@csr.utexas.edu, (512) 471-7560 Other Phone Numbers: (512) 471-5573 (CSR Secretary), -3570 (Fax) Campus Address: Mail and Express Delivery Address: University of Texas University of Texas Center for Space Research Center for Space Research Campus Code R1000 3925 W. Braker Lane, Suite 200 Austin, TX 78712-1085 Austin, Texas 78759-5321 --------------------------------------------------------------------------- [Mailed From: Richard Eanes From: Richard Eanes, University of Texas, Center for Space Research ******************************************************************************** |