SDI-COMPASS-T is a high-precision north-seeking and timing system based on GNSS positioning, direction finding and timing. The equipment integrates Beidou/GPS/GLONASS satellite navigation and positioning system, GNSS dual-antenna direction-finding system and high-precision timing, and uses carrier phase difference technology to achieve fast and high-precision positioning, orientation and timing.

The device adopts modern closed-loop control theory and Kalman digital filter technology, and uses GNSS time reference to control and tame the constant temperature crystal oscillator. The 1PPS signal output by the system is obtained by frequency division of the internal clock source, so that the output 1PPS signal is synchronized with the long-term stable value of the 1PPS signal output by the GNSS time reference, which overcomes the impact of the simple use of the second pulse signal jump of the external time reference . Therefore, the time signal output by the SDI-COMPASS-T north-seeking timing module is not only synchronized with the external GNSS time reference signal, but also more stable. The system has a self-learning function and adopts the closed-loop control timing technology. According to the aging and drift characteristics of the internal oscillator, even after the timing reference signal is interrupted or there is an interference fault, it can still output a highly stable time synchronization signal within a certain period of time. Realize high-precision timing.