中值小波阈值混合滤波在粗对准中的应用

捷联惯性导航系统的粗对准过程是实现精确初始对准的前提，也是装备精确导航定位的保证。受外界环境影响，粗对准过程存在着时间长、精度低等问题，初始对准过程的对准时间和精度也受到一定影响。通过分析陀螺和加速度计在粗对准过程中受到的干扰因素，采取中值滤波和小波阈值滤波相结合的混合滤波方法来实现信号消噪。仿真和实验证明，在外界干扰严重的前提下，采用混合滤波方法，粗对准方位姿态角标准差由47°提高至1.588°，为后续的精对准过程提供更好的数据支撑，且缩短了对准时间，提高了装备的快速反应能力。

Application of Median Wavelet Threshold Hybrid Filtering Method for Rough Alignment

Rough alignment process of Strapdown Inertial Navigation System is the premise of realizing accurate initial alignment and the guarantee of accurate navigationg and positioning. Influenced by the external environment, rough alignment process has some problems such as long time and low accuracy. The time and accuracy of initial alignment process are also affected. By analyzing the interference factors of gyroscope and accelerometer in rough alignment process, a hybrid filtering method combining median filtering and wavelet threshold filtering is adopted to realize signal denoising. Simulation and experiments show that under the premise of serious external interference, the standard deviation of rough alignment azimuth angle is increased from 47° to 1.588° by using the hybrid filtering method. It provides better data support for the subsequent precision alignment process, the alignment time is shortened and the rapid response ability of the equipment is improved.