Abstract: Device delay is the main error source in two-way satellite time and frequency transfer system. It is crucial to calibrate the delay in order to achieve highly accurate time comparison. According to the principle of two-way satellite time and frequency transfer, delay calibration based on portable station is introduced for two way satellite time frequency transfer system. In the engineering practice, due to the limit of reality, the method of calibration is modified, and the device delay of two-way satellite time and frequency transfer system is calibrated based on this method.

Key words: Two-way satellite time and frequency transfer, Device delay, ⁺Portable station