How are the P code and C/A code cycles characterized?

• A. The P code repeats every 2 weeks
• B. The P code repeats every 12 weeks
• C. The P code repeats every 38 weeks, with each week assigned to a different satellite
• D. The P code repeats every 38 weeks, and each week is assigned to a different satellite

Answer: (D)

The P code is designed as a long, time-sharing sequence whose overall pattern stretches over many weeks. In this system, each week within a 38-week cycle is assigned to a different satellite, so the P-code signal for a given satellite is unique within that week but shifts with each successive week. After the full 38-week cycle, the pattern repeats, bringing the same weekly assignments back to the start. That’s why this option describes the P code cycle length accurately: a 38-week repetition with each week tied to a distinct satellite.

In contrast, the civilian C/A code operates on a much shorter timescale, repeating its pseudorandom sequence very quickly, which is why receivers can acquire it rapidly. The key point for the P code’s behavior is the 38-week cycle with weekly satellite assignments, which is what makes the described option the best fit.