9-28C4 A
Which of the following statements is true?
A. The L2 carrier of 1227.60 MHz is used to measure the ionospheric delay.
B. The L1 carrier of 1650.5 MHz is used to measure the ionospheric delay.
C. The L1 carrier of 1545.22 MHz is used to provide the navigation message.
D. The L2 carrier of 1575.42 MHz is used to provide the navigation message.
