L2C launch delay, tests

GPS World, June, 2004

Launch of the first modernized GPS Block IIR-M satellite with a second civil signal (L2C) apparently may not occur this year after all.

A busy schedule at Cape Canaveral could push the launch back to as late as March 2005, although the satellite should be ready for launch beginning in December if a slot becomes available, according to Capt. Mike Perz, chief engineer for GPS modernization at the NAVSTAR GPS Joint Program Office (JPO). Besides the L2C signal at a 1227.60 MHz center frequency, the IIR-Ms will also introduce the new encrypted military signal (M-code).

In April, the JPO tested the L2C signal at an ITT Industries facility in New Jersey, where the navigation payload for the IIR-M is being manufactured. Various tests were run with the Trimble R7 survey system, commercially available equipment that can process the new civil signal.

JPO used a commercial simulator to imitate the GPS constellation and generate current signals. The simulated constellation was then coupled with the output from a Lockheed Martin IIR-M satellite to produce a positioning solution. According to Trimble, the tests successfully demonstrated that the Block IIR-M satellite's data can be acquired, tracked, and logged.

The next launches of nonmodernized IIRs are scheduled for June and September.