Progressive generations of satellites from GPS II/IIA to GPS III

GPS Modernization

The GPS modernization program is an ongoing, multibillion-dollar effort to upgrade the features and overall performance of the Global Positioning System. The upgraded features include new civilian and military GPS signals.

Learn more about a specific aspect of GPS modernization:

Improving GPS performance through modernization promotes the U.S. policy of maintaining leadership in the service, provision, and use of global navigation satellite systems. Learn more about U.S. policy

Schedule

GPS modernization involves a series of consecutive satellite acquisitions, including GPS Block IIR-M, GPS Block IIF, GPS III, and GPS III Space Vehicle 11+. It also involves parallel improvements to the GPS control segment, including the Architecture Evolution Plan (AEP), GPS III Contingency Operations (COps), and Next Generation Operational Control System (OCX).

We no longer provide current schedule information on this page. You can find recently released schedule information in our Public Presentations section. Go there

We also provide projected availability dates for the L2C, L5, and L1C signals on the New Civil Signals page. Go there

Funding

GPS modernization involves the complete replacement of legacy GPS satellites and ground systems with newer, more capable ones. This effort requires significant resources from the Department of Defense, with contributions from the Department of Transportation. Full details are available in our Program Funding section. Go there

Ending Selective Availability

The first step in GPS modernization took place in May 2000, when President Bill Clinton directed the Department of Defense to turn off the GPS Selective Availability (SA) feature.

SA was an intentional degradation of civilian GPS accuracy, implemented on a global basis through the GPS satellites. During the 1990s, civil GPS readings could be incorrect by as much as a football field (100 meters). On the day SA was deactivated, civil GPS accuracy improved tenfold, benefiting civil and commercial users worldwide.

In 2007, the government announced that GPS III will be built without the SA feature.

Learn more about selective availability

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