利用卡尔曼滤波估计导航信号电离层差分改正

Estimation of Ionospheric Differential Corrections of Navigation Signals with Kalman Filter

针对星基增强系统中估计电离层延迟改正数的问题,提出了利用卡尔曼滤波估计导航信号电离层延迟的方法。将电离层格网点处的电离层垂直延迟及其变化率作为状态变量进行滤波估计,根据电离层的时域缓变特性建立了状态模型,基于星基增强系统中使用的格网模型建立了观测模型。仿真结果表明,与传统的电离层延迟校正方法相比,该方法具有更高的估计精度。

To solve the estimation problem of ionospheric delay corrections within satellite-based augmentation system（SBAS）, an estimation method, which use the Kalman filter to estimate ionospheric delay of the navigation signals, is proposed. The ionospheric vertical delay and related change rate of the ionospheric grid points are estimated simultaneously. The system model is established on the basis of the slow-variant character and the measurement model is constructed on the basis of the grid model involved in the SBAS. The relevant analysis is conducted by the simulation method. The results indicate that comparing with the traditional ionospheric correcting method,this method can estimate the realtime ionospheric corrections with enough accuracy and can be an available for calculating the ionospheric differenced corrections in the SBAS.