MUNICH — The United States stands ready to use foreign satellite navigation systems as a complement to the U.S. GPS system for homeland security and other government services, including aviation-related safety-of-life applications, according to the head of the office coordinating satellite navigation systems for the U.S. government.
Anthony J. Russo, director of the U.S. National Space-Based PNT Coordination Office, said that once the non-U.S. systems meet reliability and integrity standards applied to GPS, they could be integrated into the U.S. government’s use of positioning, navigation and timing services.
After initially resisting the arrival of other satellite navigation constellations, the United States for several years has championed the idea that the nations building such systems — Russia, China, Europe, Japan and India, in addition to the United States — assure their compatibility.
Addressing the Munich Satellite Navigation Summit in Munich March 1-2, officials representing the global constellations most closely resembling GPS in reach — Russia, China and Europe — all said their governments are more willing than ever to make sure that their satellites work together without their signals interfering with each other.
Integrating four global navigation systems, plus the regional systems planned in Japan and India, into smartphones and other personal navigation devices will present challenges, they said. But the main providers have already established working groups — notably the International Committee on Global Navigation Satellite Systems, coordinated by the United Nations — to assure that this integration occurs to the benefit of users.
The U.S. space policy announced by President Barack Obama in June “went beyond” assuring compatibility to include “using [non-U.S. systems] as part of government applications,” Russo said March 1. “Studies have shown that using two systems dramatically improves performance for users. There is also an improved experience using three systems, but not as much.”
“It would be silly” for the U.S. government not to take advantage of the improved accuracy that comes from accessing more satellites, Russo said. The U.S. space policy encourages this so long as there are no compromises to safety and reliability standards.
“Those things are now things we can talk about” because of the space policy, Russo said. “We can use a foreign source if it meets the same criteria” as that demanded of GPS.
For now, GPS is the only constellation fully operational, although Russia’s Glonass system is expected to reach operational status by the end of 2011.
U.S. Air Force Col. Bernhard J. Gruber, GPS program director at the Space and Missile Systems Center at Los Angeles Air Force Base, said there are 31 operational GPS satellites in orbit, plus three other satellites that are healthy but in standby mode to be used only if needed. The full GPS system needs 24 satellites.
Gruber said the United States has signed agreements with 53 international bodies over GPS use. While the proposed fiscal-year 2012 U.S. government budget calls for a slowdown in the deployment of GPS 3 satellites starting in 2014, from four per year to two, that rate is likely to increase as the GPS 3 satellites now under contract — as many as 32 — become ready for launch.
Gruber said his office continues to study whether the second group of these satellites, batch GPS-3B, might be modified to permit two satellites to be launched on a single rocket. Up to now GPS spacecraft have been launched one at a time. “We see this as an opportunity to make better use of our resources,” Gruber said.
Russia has long launched its Glonass satellites three at a time aboard heavy-lift Proton rockets, and managers of Europe’s Galileo system, now in development, foresee launching two Galileo spacecraft at a time on medium-lift Soyuz rockets imported from Russia and operated from Europe’s Guiana Space Center in French Guiana.