Spacecraft positioning method based on pulsar-like X-ray beacon

Inspired by the X-ray pulsar navigation technology，this study proposes a spacecraft positioning method based on pulsar-like X-ray beacons，which means that artificial beacons are used to imitate pulsars to send high stabil⁃ ity and high signal-to-noise ratio X-ray signals，so as to provide positioning services for target spacecraft. Firstly，the positioning principle of the X-ray beacon based on the intersection of three spheres is introduced. On the basis of ana⁃ lyzing the influence of the signal coverage of the X-ray beacon and the gravitational perturbation of the celestial body，the scheme of arranging the X-ray beacon at the Lagrangian point in the orbit of the planets in the solar system is pro⁃ posed. Secondly，the feasibility of artificial radiation sources is analyzed and demonstrated，and the parameters of ra⁃ diation sources are preliminarily optimized based on the criteria of preferred pulsars and actual pulsar characteristics. Then，in view of the needs of Earth-Mars transfer trajectory in the future，an observation equation based on the X-ray beacon is constructed based on the spacecraft dynamics model，and the navigation filtering algorithm uses the ex⁃ tended Kalman filter method to study the influence of X-ray beacon geometry distribution，observation error，number of beacons，clock difference and orbital error on position determination accuracy. Simulation results show that under the condition of observing three beacons at the same time and the TOA measurement accuracy is 50 ns，the proposed method can achieve an optimal estimation accuracy of spacecraft position of 152 m，and most beacon combinations can control the positioning error within 1 km. Increasing the number of observation beacons has significantly improved the combination of beacons with lower positioning accuracy. However，due to the small inclination of the orbits be⁃ tween the planets in the solar system，the positioning error of the geothermal transfer orbiting spacecraft is still in the order of 100 m in simultaneous observation of 5 beacons. According to the actual needs of spacecraft in the field of deep space exploration，the positioning method proposed is expected to become an important supplement to the navi⁃ gation positioning of spacecraft in deep space exploration. © 2023 AAAS Press of Chinese Society of Aeronautics and Astronautics. All rights reserved.