Research on Combination Clock Error Prediction Under Uncertain Predicted Length

Clock error prediction is of vital importance for the distributed netted systems’ regular operation, like netted satellites, netted radars, etc. Aiming at the problem of predicted length could not get beforehand in some conditions, we put forth a combined clock error method under uncertain predicted length. We estimate the predicted length based on the clock error data quality factor in advance. Then, we operate clock error prediction based on the combination method. If the time synchronization has reestablished earlier than the predicted length, we stop prediction immediately. And if time synchronization has not reestablished when the clock error prediction reaches the predicted length, we re-estimate the predicted length and continue prediction until time synchronization reestablishes. From examples analyses, we could get 0.3–0.5 ns around precision for one-day long precision and 0.9–1.1 ns for 2 days and 1.2–1.4 ns for 1 week. Besides, we could conclude that the combination method could flat the differences of the clocks and the difference of sole algorithms, improving the robustness of the algorithm. The combination clock error prediction method could be both applied in satellites’ clock error prediction and in other distributed netted system, especially in the condition that the predicted length could not be known before predicting, being vital to the whole systems’ performance.