GPS World, January 2011

GPS Galileo GLONASS Compass SYSTEM THE Galileo Goes to Northern Extremes New Ground Control Station Opens for Coming IOV Phase Compass Rising Again K iruna Sweden 200 kilometers north of the Arctic Circle saw on December 13 the opening of a new Galileo telemetry tracking and command TTC ground station for the in orbit validation IOV satellites due to start circling Earth in 2011 Perched near the top of the European landmass Kiruna will be one of two Galileo stations to monitor the satellites and relay commands from ground controllers Kirunas extreme northern latitude gives it good visibility of medium Earth orbit satellites ensuring continuous coverage for data exchanges The remote location avoids signal interference from built up areas Galileos other ground station now online in Kourou French Guiana near the Equator opened in November 2009 Bringing ground stations online is just as important as getting satellites manufactured tested and launched The Galileo constellation will eventually require a global network of ground stations to oversee 14 or 18 or 24 or 30 satellites in space The ground segment of Galileo is getting ready in line with the space segment the operations and much more said René Oosterlinck the European Space Agencys director of the Galileo program and navigationrelated activities I have worked on Galileo since its very beginning and I am happy it is now taking shape The Galileo Kiruna station is sited at Esrange Space Center of the Swedish Space Corporation which performs control and tracking duties for a range of satellites and was previously used for the launch and early operations of the second Galileo testbed satellite GIOVE B in 2008 The facilitys 13 meter high speed antenna and all Galileo TTC equipment have been commissioned and are ready to support initial IOV operations of the satellites The station contains baseband and RF equipment monitoring control and network connections To meet stringent Galileo availability requirements all equipment is configured with internal and external redundancy The TTC station provides the interface for telemetry acquisition telecommand uplink and two way ranging The data are exchanged between the TTC stations and the Galileo Control Centers at Oberpfaffenhofen in Germany and Fucino in Italy In normal operation the TTC station is autonomous Technicians are needed for the purposes of maintenance and anomaly investigation Fleetly following an October 31 launch of the first inclined geosynchronous orbit IGSO satellite in its Compass Beidou 2 constellation China thrust a second IGSO vehicle into orbit on December 17 This makes five new satellites in space this year alone for the rapidly expanding system Plans call for seven more spacecraft to rise by 2012 completing a 14 satellite five geostationary or GEO five IGSO and four medium Earth orbit constellation to provide a regional service over eastern Asia Compass now has one medium Earth orbit two IGSO and four GEO satellites One GEO Beidou G2 is drifting in its orbit and may be unusable Long range plans envision a 27 satellite constellation providing global service by 2020 www gpsworld com January 2011 GPS World 19