What are the GPS L1 and L2 carrier frequencies?

• A. 1227.60 MHz and 1600.00 MHz
• B. 1575.42 MHz and 1227.60 MHz
• C. 1600.00 MHz and 1327.60 MHz
• D. 1575.42 MHz and 1327.60 MHz

Answer: (B)

Two main GPS carrier frequencies are used: L1 at 1575.42 MHz and L2 at 1227.60 MHz. This pairing is what lets receivers read the primary civilian signals on L1 and the second-channel signals on L2, enabling dual-frequency measurements that help correct ionospheric delay and improve accuracy. The numbers in the question that match these exact frequencies are 1575.42 MHz and 1227.60 MHz. The other options include frequencies not assigned to GPS L1 or L2, so they don’t fit.