Time Synchronization Error and Calibration in Integrated GPS/INS Systems

The necessity for the precise time synchronization of measurement data from multiple sensors is widely recognized in the field of Global Positioning System/Inertial Navigation System (GPS/INS) integration. Having precise time synchronization is critical for achieving high data fusion performance. The limitations and advantages of various time synchronization scenarios and existing solutions are investigated in this paper. A criterion for evaluating synchronization accuracy requirements is derived on the basis of a comparison of the Kalman filter innovation series and the platform dynamics. An innovative time synchronization solution using a counter and two latching registers is proposed. The proposed solution has been implemented with off-the-shelf components and tested.