Pulsar/CNS integrated navigation based on federated UKF

In order to improve the autonomous navigation capability of satellite,a pulsar/CNS（celestial navigation system） integrated navigation method based on federated unscented Kalman filter（UKF） is proposed.The celestial navigation is a mature and stable navigation method.However,its position determination performance is not satisfied due to the low accuracy of horizon sensor.Single pulsar navigation is a new navigation method,which can provide highly accurate range measurements.The major drawback of single pulsar navigation is that the system is completely unobservable.As two methods are complementary to each other,the federated UKF is used here for fusing the navigation data from single pulsar navigation and CNS.Compared to the traditional celestial navigation method and single pulsar navigation,the integrated navigation method can provide better navigation performance.The simulation results demonstrate the feasibility and effectiveness of the navigation method.

In-Orbit Calibration and Data Analysis of China＇s First Grazing Incidence Focusing X-Ray Pulsar Telescope

The grazing incidence focusing X-ray pulsar telescope(iFXPT), as the main payload of the X-ray Pulsar Navigation Test Satellite(XPNAV-1), will have great significance on China's space scientific exploration and X-ray pulsar navigation. With PSR B0531+21(Crab Pulsar) as the observation target, the pulsar profile has been recovered based on the data obtained by iFXPT, realizing the main objective of "observing" PSR B0531+21 for the first time in China. This payload mainly consists of the Wolter-I X-ray optics, silicon drift detector, magnetic deflector, electronics, high-energy particle shield and high-stability structures. Currently, the iFXPT, with its good in-orbit performance, has obtained a considerable observation data. The effective area, sensitivity and energy response have been calibrated both on ground and in-orbit, demonstrating a high degree of consistency. Meanwhile, the in-orbit observation data and information for pulsar navigation has also been analyzed simultaneously. As a result, the feasibility of the exploration scheme and the performance of the telescope have been fully validated.