一种近地航天器脉冲星地固系动力学定轨方法

为改善近地航天器脉冲星导航的定轨精度，设计一种地固系动力学定轨方法。该方法结合了更精确的地球引力场模型，在求地球引力势梯度基础上引入惯性力，建立了地固系下轨道动力学方程；并结合脉冲相位量测，使用扩展卡尔曼滤波实现航天器轨道参数实时估计。此方法可以降低动力学方程非线性度，尤其适用于地球静止轨道卫星。通过数学仿真校验了新方法的有效性与精度。

A Method of Pulsar Based Dynamic Orbit Determination in the Earth Fixed Reference Frame for Near Earth Spacecraft

To improve the navigation accuracy by properly incorporating the Earth gravity model in the near-Earth spacecraft pulsar-based navigation, this paper proposes the method of dynamic orbit determination in the Earth-fixed reference frame. Based on the geopotential and the inertial force model, the obit dynamics equation is constructed in the Earth-fixed reference frame. The pulse phase measurement is used in the extended Kalman filter for real-time estimation. The proposed method decreases the nonlinearity of the dynamics equation, which is especially applicable for the geostationary satellites. Numerical simulation validates the effectiveness and the accuracy of this method.