GPS Modernisation

The modernization of GPS satellites brings new signals, named L2C and L5, on the latest generation of GPS satellites.

Extra signals
L2C is a new code signal on the L2 frequency, allowing direct access to the L2 signal, instead of having to acquire the L1 frequency first. The net result is better tracking and quicker re-acquisition of the GPS signals. The L2C signals are available on generation GPS IIR (M) satellites.

L5 is an additional (third) carrier frequency in the GPS signal. This signal will be of great benefit as it allows faster RTK initialisations. It will be available in the so called Block IIF satellites.

For a detailed description see  http://www.navcenter.org/gps/modernization/default.htm , in particular the article The New L2 Civil Signal (PDF) in the L2 section on this page. Note that the time planning of the GPS Modernization has been pushed back a number of times.

When-o-When is it available?

The GPS modernization will take years to be available on all satellites, although the benefits will be available even if just a few satellites are updated. The GSR2700ISX and other receivers which are capable of tracking L2C and L5, require a firmware update to enable this capability. This firmware update will be made available when a sufficient number of satellites broadcasting the modernised signals are operational.

The L2C raw data is available now in the GSR2700ISX receiver and can be exported to RINEX format with Spectrum Survey version 4.0 and later.
And if your software actually can't handle the new measurements, see our support section.

L2C was available first on satellite PRN 17, since Dec 2005, with the second (PRN31) launched in Sept 2006 and third one (PRN 12) on 17 November 2006. PRN 15 was launced Oct 2007, PRN 29 was launched 20 Dec 2007. The sixth satellite PRN07 was launched on 15 March 2008.

The roll out of L5 istarted with the launch of the first Block IIF satellite scheduled for June 2008

For a bit of sobering reading regarding all these beautiful new gottahaves, have a look at this article in GPSworld (May 2008)