A 1.023MHz Pseudo Random Noise (PRN) Coarse/Acquisition (C/A) code sequence is added to this data. With the help of L-Band carrier frequency signal (L1) of 1575.42 MHz, the satellite modulates the resulting code sequence to create a spread spectrum ranging signal.
This SPS ranging signal which is right-hand circularly polarized in nature gets broad-casted to all the users on earth. Each Coarse/Acquisition code is unique and distinctively identifies each satellite in the constellation. There is also a second SPS ranging signal known as L2 which facilitates users for two frequency correction. L2 is broadcasted at 1.2276 GHz. The signal generation at satellite end is illustrated by Fig.