... The navigation data rate carried by the P code through phasemodulation is at a 50 Hz rate.5.5 C/ A CODE AND DATA FORMAT(1,2,5)The C/ A code is a bi-phase modulated signal with a chip rate ... ofthe transmitting satellite. The MSB (bit77) indicates a summary of thehealth of the navigation data, where bit77 equals:0 All navigation data are OK.1 Some or all navigation data are bad.5.18 ... and Applications, vols.1 and2, American Institute of Aeronautics and Astronautics, 370 L’Enfant Promenade,SW, Washington, DC,1996.12. van Graas, F., Braasch, M. S., “Selective availability,”...