Coordination and Synchronization of Loran-C and GPS to Universal Coordinated Time.

摘要

Public Law 100-223, the Airport and Airway Safety and Capacity Act of 1987, requires an analysis and report to Congress on the impact to current users of synchronizing loran-C secondary stations to within 100 nanoseconds (ns) of Universal Coordinated Time (UTC), and the methods and impact of coordinating the time references of the loran-C and GPS systems to within 30 ns of each other. This report provides the analysis required by the law. The impact on repeatable accuracy of the five loran-C chains covering the United States (excluding Alaska and Hawaii) is analyzed using the Double Range Difference (DRD) model. The model is modified to predict system repeatability in the UTC synchronized environment, when the control strategy excludes use of a System Area Monitor (SAM). Charts showing the loran system repeatable accuracy under SAM control, and under control regimes synchronizing master and secondary stations to within 0 ns (perfect time-of-emission control), 30 ns (1o), and 100 ns (1o) of UTC are shown.