Design of Satellite Ranging System Based on Physical Random Sequence

A setup of satellite ranging based on phsical random sequence is demonstrated, which has absolute security in information transmission because of the random property of the physical sequence. Using true random sequence replacing pesudo random sequence, synchronization technology is vital important for transmitted information demodulation, despreading and decryption. Based on the pricinple of telemetry tracking and controlling system and unique properties of the phsical random sequence generating device named weakly coupled GaAs/Ga0.55Al0.45As superlattices, a combined synchronization control system is designed, which combined the out reference clock synchronization with the chaotic synchronization. Moreover, a ranging system based on noncoherent physical random sequence spread spectrum method is investigated in detail, which is an important part of the satellite tracking and controlling system. Introduction An all-electronic physical random number generator that can generate random number up to 80 Gbit/s at room temperature was demonstrated in recent years, which has important potential applications in information security of satellite telemetry tracking and controlling (TT&C) area [1]. In reality, most random numbers used in computer programs are pseudo-random, which means they are generated in a predictable fashion using a mathematical formula [2-6]. This is fine for many purposes and is enough to use in many area, but it may not be random enough in normal information secure [7-10]. Ranging system is an important part of the satellite tracking and controlling system that is an information channel between the satellite and ground station opening a window to ensure the satellite being in accordance with the expected orbit and attitude. At present, generally radio wave is used for ranging in TT&C. There are four major type methods named pulse radar ranging, pure side tone ranging, pseudo code ranging and sound code mixed ranging, which are very mature. However, if true random sequence replaced pesudo random sequence for spreading and encryption, the system referring time synchroniztion should be redesigned no matter coherent or noncoherent random sequence ranging methods being used. In this manuscript, the theories of random sequence encrypttion and ranging are firstly investigated. Then, information exchange between satellite and ground station model is designed. At last, a combined synchronization control system is designed, which combined the out reference clock synchronization with the chaotic synchronization.