PARIS — Four European governments have begun testing the quasi-military signals planned for the Galileo constellation of positioning, navigation and timing satellites to assure that ground hardware is available to government users when the constellation is operational, the European Space Agency (ESA) said Sept. 2.

The test campaigns in Belgium, France, Italy and Britain have been conducted under the PRS Participants to In-Orbit Validation program, whose aim is to assure the rapid entry into use of ground gear for Galileo’s Public Regulated Service (PRS).

The PRS signals are the European equivalent of the military code being placed on the U.S. GPS satellites. They are designed to be jam-resistant and reserved for civil and military government users in Europe.

The tests so far have demonstrated a 10-meter-accuracy positioning for PRS, which ESA said is a good result given that only four Galileo satellites are in orbit and that the ground infrastructure has not yet been completed.

PRS testing had been scheduled to start after several full-operational-capability Galileo satellites were operational. But these satellites’ launches have been delayed while ESA verifies the satellites’ functionalities and are now unlikely to start before early 2014.

In addition to the four governments doing their testing through their national Galileo installations, ESA has been conducting its own series of PRS tests, on fixed and mobile terrestrial platforms, at the agency’s centers in the Netherlands and Italy.

ESA said tests of PRS on aircraft would start this fall. The agency is performing its testing in conjunction with Italian and Dutch authorities.

One issue facing PRS users is how well the service will work given that the PRS signals use radio spectrum partially overlapping the secure, government-reserved signals used by China’s Beidou navigation constellation. Galileo managers have increased the power available to PRS on the satellites to be launched starting in 2014 in response.

The overlap does not cause either system any operational difficulties, but could be an issue in the event China or Europe sought to jam the other’s signals during a crisis.

Peter B. de Selding was the Paris bureau chief for SpaceNews.