U.S. Confirms Plans for GPS Semi-Codeless Transition

The U.S. government has committed itself to maintaining the signals characteristic needed for semi-codeless GPS applications until December 31, 2020.

The U.S. government has committed itself to maintaining the signals characteristic needed for semi-codeless GPS applications until December 31, 2020.

In a September 23 notice in the Federal Register posted by the office of John Grimes, Assistant Secretary of Defense for Networks and Information Integration (ASD-NII)/DoD Chief Information Officer, the plan will ensure that civil users can continue employing codeless or semi-codeless techniques to gain access to encrypted GPS signals, L1 P(Y) and L2 P(Y), for high-accuracy, dual-frequency applications.

Based on the current launch schedule and projected budget, the transition date represents the planned availability of the second (L2C) and third (L5) coded civil GPS signals being broadcast from a minimum of 24 GPS satellites — a standard known as full operational capability (FOC). FOC for L2C and L5 is expected to occur in 2016 and 2018, respectively.

According to the Federal Register notice, after the transition date, the characteristics of the L1 P(Y) and L2 P(Y) signals transmitted by any or all GPS satellites broadcasting two or more civil-coded signals may change without further notice and may preclude the use of P(Y) coded signals for high accuracy applications.

The final notice came after a completion and review of a public comment period earlier this year.