Study on a novel approach for time synchronization data integrity monitoring

Time synchronization of satellite navigation system sets high requirement for integrity of measurements. Conventional integrity monitoring method such as Shewhart control chart and CUSUM control chart are adaptable to specific errors. Shewhart control chart is good at detecting large shift of measurements but can not detect continuous shift. On the contrary, CUSUM control chart can detect continuous small shift of measurements effectively but has large average run length (ARL) when detecting large shift. This paper proposes a combined Shewhart-CUSUM algorithm; this new control chart improves average run length by changing state transition probabilities. We derive ARL of Shewhart-CUSUM control chart in different configuration and research parameter selecting method. Software simulation indicates that combined Shewhart-CUSUM control chart can detect both large and small shifts effectively.