Inter-Satellite Links Study for GEO/MEO Satellite Network

Based on navigation constellation with GEO and MEO satellites, this article analyzes the inter-satellite links (ISL) characteristic of two-layer satellite network. First, the mathematical models of ISL distance, azimuth and elevation were established by the Hill equation. Second, the relative motion of satellites and the construction of constellation were used to confirm the three basic criteria which can reflect the space geometric characteristics of the ISLs, and furthermore give a mathematical criterion of the constellation full connectivity. Finally, the ISL budget was taken to help to allocate rationally the antenna gain and transmission power of navigation system, and make sure the requirements of satellite transmission speed and ranging indicators for the autonomous navigation. Simulation is carried out, and finally illustrates the connection between satellites and composes the information network to guarantee full connectivity of the navigation constellation.