%A CUI Xiao-Zhun, MI Hong, LI Yi, CHEN Zhong-Gui %T A Delay Measurement Algorithm of C/A Signal Transmission Channel for GPS Satellite %0 Journal Article %D 2012 %J Journal of Shanghai Jiao Tong University %R %P 1843-1847 %V 46 %N 11 %U {https://xuebao.sjtu.edu.cn/CN/abstract/article_40180.shtml} %8 2012-11-30 %X The delay measurement accuracy of the transmission channel directly affects GPS users’ positioning precision and time transfer accuracy of GPS. To measure delay of C/A (Coarse/Acquisition）signal transmission channel high accurately, a delay measurement algorithm based on DSP (Digital Signal Processing) was introduced. The C/A signal and the pulse of Z counter of time keeping system on GPS satellite are sampling in synchronization. After C/A signal data pre-processed, multi-rate digital processing is made to decide the start point of PRN (Pseudorandom noise) code of C/A signal. With the processing results of Z pulse signal data, the delay of C/A signal channel is calculated out. The measurement uncertainty with the proposed algorithm is less than 0.2 ns when the sampling frequency is 10 Gsa/s.