Study of a Forwarding Approach of Satellite Time Service

To reduce the dependence on the high-precision time service provided by the GPS, it is desirable for our country to establish a low-cost and high-precision time service system of independent intellectual property rights. In this paper, we present a new method of satellite time service achieved through the broadcasting of a communication satellite and using a high-stability ground-based atomic clock as the time-frequency reference. We study the theory and measurement of multiple-satellite and single-satellite time services with the navigation constellations constituted by high-stability ground-based atomic clocks and communication satellites. We particularly analyzed factors affecting time accuracy in these two types of methods. Because of the high stability of the time-frequency source our proposed forwarding approach of satellite time service can have improved ranging accuracy. As long as the systematic error of time delay is precisely corrected, highly accurate time service can be achieved with our approach as well: Time accuracy with the coarse acquisition code can be within 20ns and that with the fine short code is about 10ns. In short our proposed system has the advantages of flexibility, convenience, and broad applications.