Application of STEKF in X-ray Pulsar Based Autonomous Navigation

Abstract

The navigation of X-ray pulsar depend on the signal of X-ray pulsar radiation as an information input, through the corresponding signal and data processing, provide for navigation information of spacecraft position, velocity and attitude for near-Earth orbit, deep space and interstellar space flight, to achieve high-precision autonomous navigation of spacecraft. This paper introduces the principle of pulse satellite navigation established on the basis of the X-ray pulsars, autonomous navigation system, the state equation and observation equation. Select the three pulsars, using extended Kalman filter (EKF) and strong tracking extended Kalman filter (STEKF) algorithm, for satellite operation of the position and velocity estimation carried out simulation experiments. Simulation results show STEKF through the introduction of fading to dynamically adjust the gain matrix, to extract the maximum output of the residuals of all the useful information, making adaptive filter to correct the estimated bias and the ability to fast track the state changes, overcome the EKF defects in filtering performance degradation caused by the more complex non-linear navigation model due to uncertainty. Therefore, STEKF has higher valuation accuracy, numerical stability and strong traceability than EKF,and broad applicability in the autonomous celestial navigation.