基于GPS与三轴磁强计的联合导航算法

为了修正近地轨道(小于1000 km)地磁场模型,提高导航的精度,在地磁导航系统中引入GPS作为一个新的测量设备,提出了一种基于三轴磁强计与GPS的联合导航算法．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GPS接收的信号作为观测量,建立观测方程;并以GPS确定的轨道状态量为标准量,去估计磁场模型参数的修正量,构成冷备冗余导航算法．仿真结果表明,提出的导航算法对轨道位置的估计误差小于50 m,速度的估计误差小于0．1 m／s,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．

Combined Navigation Algorithm by Means of Magnetometers and GPS

In order to refine the geomagnetic model of LEO (Low Earth Orbit) and to improve the precision of navigation, it introduces GPS as a new measure instrument and proposes a combined navigation algorithm based on three-axis magnetometer and GPS. Using the position and velocity of the satellite as state vectors and using the intensity of the magnetic field and signals of GPS as observed values, this algorithm establishes the state equation and observation equation respectively. The orbit states which are deteminated by GPS navigation system are used to estimate corrections of geomagnetic model. The simulation result shows that the estimation error of orbit position is less then 20 meters and velocity estimation error is less than 1 meter per second. The veracity and convergence of this navigation algorithm are better than mono-geomagnetic navigation system.