Abstract: The segment correlation-video integration method for pseudo-random noise code signals using differential detection under carrier Doppler is studied.The statistic performance for this method is derived in mathematics,and the formula of detection loss is analyzed.Using the criterion of minimizing the maximum of detection loss,the method for both cases with a given total integration time and the given detection performance(detection and false alarm probabilities) is optimally designed.Compared with the square-law detection,the differential detection is preferable to the square-law detection at the high carrier Doppler and low signal-to-noise ratio.