Delivered-To: igsmail@igscb.jpl.nasa.gov Message-ID: <03C99297F33C9648AF9E24FF90FCCD2A017D4108@cluwsh04.gold.rtgold.nima.mil> From: "Slater, James A. " To: "'igsmail@igscb.jpl.nasa.gov'" Subject: [IGSMAIL-4771]: Timely Rapid and Final GLONASS Orbits Available from CODE Analysi s Center Date: Fri, 19 Dec 2003 11:56:21 -0500 Sender: owner-igsmail Precedence: bulk ****************************************************************************** IGS Electronic Mail 19 Dec 08:57:21 PST 2003 Message Number 4771 ****************************************************************************** Author: Jim Slater Please disregard this message if you already received it via IGLOSmail. Since 8 June 2003 (GPS Week 1222), the CODE Analysis Center at the University of Bern has been computing rapid and final orbit products for the GLONASS satellites. CODE generates these GLONASS orbits at the same time as the GPS rapid and final orbits. (Reference IGSMail-4474.) The final CODE GLONASS orbits are in the same ephemeris file as the GPS final orbits and are not available separately. At the NASA CDDIS Data Center, the final GLONASS orbits from CODE can be found at ftp://cddisa.gsfc.nasa.gov/pub/gps/products by week number in the files labeled "codnnnnd.eph.Z" where 'nnnn' is the GPS week no. and 'd' is the day of the week (0-6). The GLONASS rapid orbits can be found only at the CODE website at http://www.aiub.unibe.ch/download/CODE in the files labeled as "CODnnnnd.EPH_R". Predicted rapid orbits are in the files labeled as "CODnnnnd.EPH_P". These rapid orbit files include both GPS and GLONASS satellites. Lists of the IGS stations used to compute the final and rapid GLONASS orbits for each day can be found at http://www.aiub.unibe.ch/download/igsdata in the files labeled "glonass_final.txt" and "glonass_rapid.txt". The timely availability of the CODE GLONASS orbits should facilitate the use of the GLONASS data for a number of applications such as time transfer, and ionospheric and tropospheric modeling. This is especially relevant due to the recent launch of three GLONASS satellites, bringing the potential operational GLONASS constellation to 11 satellites. BKG, ESA and MCC also compute GLONASS orbits, but these are generally not available for 3-6 weeks; and the combined GLONASS orbit product can only be generated after all the individual analysis centers submit their final orbits. Only CODE generates a rapid orbit for the GLONASS satellites and its final orbits do not have the latency problem associated with the other analysis centers. ............................................................................ ................ JIM SLATER (301)227-4549 Fax: (301)227-2837 E-mail: slaterj@nima.mil NGA, PPSC, MS D-68, 4600 Sangamore Rd., Bethesda, MD 20816-5003, U.S.A. "Discovery consists of seeing what everyone else has seen and thinking what no one else has thought" -Albert Szent-Gyorgi