Point of Beginning

Galileo Satellites Mark Beginning of New Era in Global Positioning

November 2, 2011

On Oct. 21, the first two satellites for Europe's Galileo global navigation satellite system were launched into orbit from Europe’s Spaceport in French Guiana by a Russian Soyuz vehicle. According to the European Space Agency (ESA), all of the Soyuz stages performed perfectly, and the Fregat-MT upper stage released the Galileo satellites into their target orbit at 23 222 km altitude, 3 hours and 49 minutes after liftoff.

“This launch represents a lot for Europe: We have placed in orbit the first two satellites of Galileo, a system that will position our continent as a world-class player in the strategic domain of satellite navigation, a domain with huge economic perspectives,” said Jean-Jacques Dordain, director general of ESA. “This launch consolidates Europe's pivotal role in space cooperation at the global level.”

The launch and early orbit phase (LEOP), which is being overseen by a joint ESA and CNES French space agency team in Toulouse, France, is expected to end Nov. 2. Routine operation of the satellites will then be handed over to SpaceOpal, a joint company of the DLR German Aerospace Center and Italy's Telespazio, to undergo 90 days of testing before being commissioned for the In-Orbit Validation (IOV) phase, in which the Galileo system’s space, ground and user segments will be extensively tested. The next two Galileo satellites, completing the IOV quartet, are scheduled for launch in summer 2012.

Dru A. Smith, PhD, chief geodesist for NOAA’s National Geodetic Survey (NGS), said the agency is already anticipating related changes in the GNSS as noted in its 10-year plan. The plan states, in part, “Three GNSS-related issues must be addressed for the CORS network to remain a viable tool for accurate positioning in the NSRS [National Spatial Reference System]. First, the changing world of GNSS must be accounted for. That is, as new signals and constellations become available, NGS must assure that new and replaced CORS hardware accounts for these changes. (Aside from foundation CORS, equipment at existing CORS will not be required to be upgraded until a component fails, at which time the replaced component will need to align with NGS policy on CORS and GNSS). Second, NGS must provide users with software that will use any and all GNSS signals. That is, OPUS-GNSS must allow for every possible scenario from single frequency, pseudo-range GPS positioning with one second of data to triple constellation, multiple-frequency, 24-hour carrier-phase surveys with multiple antennas in an array, and everything in between. Third, orbit determination software used at NGS must encompass all GNSS changes, for complete support to be possible.”

Ten-year milestones set by the NGS with a completion goal of 2018 include NGS providing 1-centimeter orbits for GPS, GLONASS and Galileo, and 1-centimeter access to geodetic latitude, longitude and height to all GNSS (generic) users, without regard to constellation, with less than four hours of data anywhere in the United States or its territories.

Joseph V.R. Paiva, PhD, PS, PE, a geomatics consultant and POB contributing editor, said that surveyors won’t immediately reap benefits from the Galileo satellites. “There is some risk that information from the data collected once [the satellites] go online may cause delay in all future launches,” he said. “Considering how fast satellite receivers become old technology, there is no particular reason to hurry out and buy receivers which include Galileo capability.” Still, he noted that the launch indicates the first sign of considerable progress towards potential use of the Galileo system, perhaps by 2013 or 2014.

David Doyle, chief geodetic surveyor for NOAA’s NGS, agreed that there is reason to be optimistic. “It should mark the beginning of what we all hope will be significant improvements in global positioning, timing and navigation,” he said. “It will still be some time until there are a sufficient number of satellites in the Galileo constellation to practically contribute to day-to-day surveying and mapping activities, but it is a very good beginning.”