基于三轴磁强计与雷达高度计的融合导航算法

为了减小近地轨道(小于1000km)地磁导航的估计误差协方差，提高导航的可靠性和准确性，在地磁导航系统中引入雷达高度计作为一个新的测量设备，提出了一种基于三轴磁强计与雷达高度计的融合导航算法。该算法取卫星的位置和速度向量作为状态向量，建立状态方程；取卫星周围的磁场强度和卫星到星下点实际海平面距离求出的地心距，作为观测量建立观测方程；利用扩展卡尔曼滤波构成一种融合导航算法。仿真结果表明，提出的融合导航算法对轨道位置的估计误差小于20米，速度的估计误差小于1米／秒，导航算法的精度和收敛性都优于使用单一地磁导航的系统。

Satellite Autonomous Orbit Determination Using Magnetometers and Radar Altimeter

The paper introduced radar altometer as a new measure instrument and proposed a fusion navigation algorithm based on three-axis magnetometer and radar altimeter for decreasing the estimated error covariance of magnetometer-based near earth (less than 1000km) satellite orbit navigation and improving the reliability and veracity of navigation. Using the position and veracity of the satellite as state vectors and using the intensity of the magnetic field and geodetic altitude which is from the satellite to the subsatellite point at the sea level as observed value, this algorithm established the state equation and observation equation respectively. The simulated result shows that its estimated error of orbit position less then 20 meter and velocity estimated error less than 1 meter per second. The veracity and astringency of this navigation algorithm is better than mono-geomagnetism navigated system.