Abstract: A design and implementation of automatic calibration software of fraction code delay for RNSS （Radio Navigation Satellite Server） signal transmitting channel for navigation satellite based on Matlab GUI is presented. The software controls a high sampling rate digital oscilloscope through GPIB interface. The Navigation satellite BPSK transmission signal and pules per second signal are sampled. With a digital signal processing algorithm, the phase transform point corresponding to chip level changement is determined, then fraction chip delay is obtained. The interface of software is friendly. The operation of software is easy and the display of the processing result is visual. The software has been applied to the integration test of navigation satellite.

Key words: Navigation satellite, Fractional code delay, Calibration, Software