Delivered-To: iglosmail@igscb.jpl.nasa.gov Message-ID: <03C99297F33C9648AF9E24FF90FCCD2A017D412E@cluwsh03.gold.rtgold.nima.mil> From: "Slater, James A. " To: "'iglosmail@igscb.jpl.nasa.gov'" Subject: [IGLOSMAIL-941] Status Report - IGLOS Pilot Project Date: Mon, 5 Jan 2004 15:55:15 -0500 Sender: owner-iglosmail Precedence: bulk ****************************************************************************** IGLOS Electronic Mail 05 Jan 12:56:28 PST 2004 Message Number 941 ****************************************************************************** Author: Jim Slater The following status report was presented at the IGS Governing Board Meeting in San Francisco on 7 December 2003. GLONASS Constellation Status As of the first week of December, there are eight healthy GLONASS satellites and two designated as "unusable". A new launch is scheduled for 10 December 2003. [ Three new GLONASS satellites were successfully launched.] IGLOS Tracking Network At present, there are 45 official operational IGS stations that are observing GLONASS satellites. Four additional stations have not submitted updated site logs and therefore are treated as unofficial stations. The latter include McMurdo Station (CRAR) in Antarctica, Neustrelitz (NTZ1) in Germany, Ferrara (UNFE) in Italy, and Gjovik (GJOV) in Norway. International Laser Ranging Service (ILRS) Tracking The ILRS stations have primarily tracked three GLONASS satellites - Russian GLONASS Numbers 788, 789 and 791 in orbit plane 3/slot 24, plane 1/slot 3 and plane 3/slot 22, respectively. The laser ranging data stored at the CDDIS between 1 January and 3 December 2003 are tabulated below. GLONASS satellite number 790 has been unhealthy since January 2003 and was replaced in the ILRS satellite tracking priority list by GLONASS satellite 791 at the request of the IGS. GLONASS Satellite ILRS No. of No. of No. of No. Plane/Slot GLONASS No. Stations Normal Points Passes 788 3/24 84 26 6,719 1,404 789 1/3 87 27 5,113 1,121 790 1/6 86 19 1,446 236 791 3/22 89 22 7,919 1,668 Precise Orbit Computation Effective 8 June 2003 (GPS Week 1222), the CODE Analysis Center began to produce GLONASS satellite orbits as part of its routine IGS orbit processing. CODE generates both final and rapid GLONASS orbit products that are available essentially simultaneously with the GPS orbit products. For the 90-day period between Days 249 and 338 in 2003, the number of GLONASS stations reporting observations in time for the rapid orbits varied from 15 to 26, while the number of stations used for the final orbits ranged from 22 to 30. This is a significant development in the availability of GLONASS products. BKG, ESA and MCC continue to produce precise orbits with about a 4-5 week lag time. The final orbit accuracies are better than 20 cm. GLONASS Data Product Usage Statistics compiled from NASA's CDDIS for the number of files of GLONASS data products downloaded from 1 January to 30 October 2003 give provide some limited insight into the users of the products. The CODE orbits and other combined GLONASS-GPS products are not included in this after GPS Week 1222 (8 June). This figures do not include the observation files that are now embedded in the combined GPS/GLONASS RINEX observation files. In the 10-month period, there were 6,285 downloads ranked by country as follows: Russia 2,520 France 48 International 1,529 Spain 47 Austria 808 U.S. Commercial 38 U.S. Network 685 Switzerland 37 U.S. Military 301 U.S. Education 26 Germany 93 Iran 14 Italy 92 U.S. Government 12 Other countries accounted for less than 10 downloads each for the 10 months and included Argentina, Australia, Chile, China, Czech Republic, Japan, Norway, Peru, Poland, Portugal, South Korea, United Kingdom and Yugoslavia. The "International" designation is mainly ESA. "Network" implies an internet service provider such as AOL or MSN. Categorized by user type, "government" users represented almost two-thirds of the users, educational institutions about 16% and "network" users about 19%. ............................................................................ ................ 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. "It is better to know some of the questions than all of the answers" -James Thurber