Experiments in Precision Common Time for Mobile Platforms; Conference paper

摘要

Various naval applications can benefit from the synchronization of clocks across mobile platforms, particularly if the time synchronization is accomplished at the few-nanosecond level. The Naval Surface Warfare Center, Dahlgren Division, has undertaken the task of merging precise point positioning capabilities with common view mode techniques to demonstrate the capability of determining relative clock offsets in real time to the nanosecond level for clocks on mobile platforms. These demonstrations compare the GPS-derived clock offsets between the USNO Master Clock and a portable rubidium clock that supports an Ashtech Z12-T and is carried in a van that is located approximately 60 km from USNO. The data are postprocessed as if they were collected and processed in real time. The Kalman filter estimates of the relative clock offsets are compared to the measured clock offsets that are determined by comparing the rubidium clock to a portable cesium clock that was synchronized with the USNO Master Clock. After adjustment for a system bias, the estimated clock offsets agree with the measured clock offsets to the few-nanosecond level. These demonstrations have provided the incentive for integrating this capability with various measurement systems that could benefit from this level of clock synchronization.