China has switched on its own satellite navigation system, marking a big step forward for a nation eager to reduce its reliance on the West for key strategic technologies.

American researchers are unveiling a new tool for detecting illegal nuclear explosions: the Earth's global positioning system (GPS). Even underground nuclear tests leave their mark on the part of the upper atmosphere known as the ionosphere, the researchers discovered, when they examined GPS data recorded the same day as a North Korean nuclear test in 2009. Within minutes on that day, GPS stations in nearby countries registered a change in ionospheric electron density, as a bubble of disturbed particles spread out from the test site and across the planet.

Developed nations have become "dangerously over-reliant" on satellite navigation systems such as GPS, which could break down or be attacked with devastating results, British engineers said Tuesday.

The head of the U.S. Air Force said today that the military needs to wean itself off dependence on a GPS network vulnerable to jamming and satellite-killing vehicles. DOD Buzz reports that officials have confirmed that GPS has been "jammed or interfered with recently."

The Global Positioning System faces the possibility of failures and blackouts, a federal watchdog agency has warned the U.S. Congress. Mismanagement by and underinvestment by the U.S. Air Force places the GPS at risk of failure in 2010 and beyond.

China’s membership of “Galileo,” the European-led version of America’s Global Positioning System (GPS), has soured to the point where the two sides are locked in a dispute over radio frequencies, as China races ahead with its own network of satellites.

In the latest of a series of setbacks for the Galileo navigation satellite project, a European bid to create an alternative to the U.S. Global Positioning System, China is set to claim a frequency that the European Commission wants to use for a security-oriented portion of the service.

Chinese satellite navigation officials say they intend to field an operational system covering all of Asia by 2010, but they are giving few details on the deployment plans for their global system. In addition China has yet to complete frequency coordination with the United States, Europe, Russia and others.

The European Union's most ambitious technological project, a satellite navigation system designed to provide users with unprecedented accuracy, faces disaster as it remains mired in vicious disputes among the eight companies chosen to build and operate the system.

Political infighting is undermining the European Union's biggest ever joint technology programmeme: the Galileo satellite navigation network.