Research on navigation and positioning Technology based on opportunity signal of low orbit satellite

Abstract

Global Navigation Satellite System (GNSS) signals to the Earth’s surface are weak, vulnerable to interference, and require significant infrastructure investment to keep them operating. In order to get rid of the dependence on GNSS navigation system and overcome the problems such as shadow occlusion and malicious interference, opportunity signal is used to realize positioning to make up for the shortcomings in this aspect. Aiming at the limitation of coverage and availability of land-based opportunity signals at present, the opportunity signals of low-orbit satellites have the advantages of high signal power, wide coverage and no need to build additional infrastructure, etc. Therefore, space-based opportunity signal positioning by using low-orbit satellite system can be used as an effective backup or supplement to GNSS system. In this paper, the signal communication system of low orbit satellite is studied deeply, and the Doppler frequency information is obtained by using the single tone signal of the pilot frequency of low orbit satellite, and the mathematical model of instantaneous Doppler positioning and its geometric factor of accuracy is established, so as to realize the positioning ability of opportunity signal of low orbit satellite. The simulation results show that the positioning accuracy is better than 200 m using the actual low orbit satellite signals. The research results have reference significance for the theoretical research and application of location technology based on opportunity signal. By studying the communication system of low orbit satellite signal, the mathematical model of instantaneous Doppler positioning is established, and the method of obtaining Doppler frequency information by using the single tone signal of low orbit satellite signal and combining the satellite orbit information calculated by the orbit prediction model to realize low orbit satellite positioning is proposed. The measured data verification results show that the positioning accuracy of 100 meters can be achieved by using the LORB opportunity signal, and the research results have reference significance for the theoretical research and application of positioning technology based on the LORB opportunity signal.