An Aerospace Layering Time Synchronization Architecture and Intersatellite Microwave Links Performance Analysis Based on 3-Layer Satellite Networks

摘要

The rapid development of various kinds of aerospace application systems requires the appropriate high-accuracy time and frequency standard. This problem can be effectively solved by establishing suitable time and frequency standard in aerospace. Based on the establishment of aerospace satellite visual model, the simulation of satellite visual time on 3-layer satellite networks, including GEO satellite(Geostationary Earth Orbit), IGSO (Inclined GeoSynchronous Orbit)satellites and MEO(Medium Earth Orbit) satellites, has been conducted. The visual features of this satellite network have been gained. Combining with the major influencing factors of satellite clock correction error, an aerospace time synchronization architecture on the basis of layering has been proposed. Furthermore, intersatellite links performance analysis is the basis for establishing aerospace layering time synchronization architecture. The 3-layer satellite networks is used as an example to simulate the variation range of distance interlayer satellites of the 3-layer satellite networks and to analyze the performance of GEO-IGSO, GEO-MEO, and IGSO-MEO links in S-band and Ka-band under the preset intersatellite transmission system, link parameters, transmission loss and without regard to the error of the intersatellite pointing accuracy. The results show that at the maximum intersatellite distance, if the S-band transmission rate is in excess of 2Mbps,when the antenna is 1m in diameter, the transmitting power needed is about 50W. In the Ka-band, 1m antennas only need 1W transmitting power to provide an intersatellite data transmission rate higher than 2Mbps. The Ka-band is more favorable for improving the performance of intersatellite links of 3-layer satellite networks. Research results serves as reference for the establishment of aerospace layering time synchronization architecture based on 3-layer satellite networks.