基于欧拉四面体的下降轨雷达图像定位方法

导弹在末制导阶段因惯导误差导致弹体实际位置和惯导指示位置存在较大偏差，影响导引头对目标的准确定位，无法满足精确打击的应用需求。由于弹载合成孔径雷达在导弹俯冲下降段特殊的成像几何构型，目标点对应斜视角所在的平面与成像平面异面，因而传统的基于多普勒测角的定位方法已不再适用。该文利用图像匹配获取的高精度地面点相对位置信息和雷达到各目标点的高精度斜距信息，通过构建欧拉四面体几何模型，以场景数字高程作为先验信息筛选参考点，解算出以目标点为原点构建的北天东坐标系下的弹体实际位置，从而为弹体修偏提供准确信息。仿真实验验证了该定位方法能很好地满足导弹末制导阶段的目标定位需求。

Radar Image Positioning Method on Decent Trajectory Based on Euler Tetrahedron

There is a large deviation between the actual position of the missile and inertial guidance position in the final guidance stage due to the inertial navigation error, which influences seeker,s accurate on positioning to the target, so it can not meet the application needs of precision strike. Due to the special imaging geometry of the missile borne Synthetic Aperture Radar (SAR) in the descending section, the squint angle plane of the target point is different from the imaging plane, so the traditional positioning method based on Doppler angle measurement is no longer applicable. This paper uses image matching to obtain high precision ground point relative position information and the high precision slant range information between radar and target point. By constructing a Euler tetrahedral geometry model, using the scene digital elevation as a priori information to screen the reference point, the actual position of the missile in the established North-sky-East coordinate system with an origin of the target point is calculated. Then it can provide accurate information for the missile maintenance. Simulation results show that this method can meet the requirements of target positioning on missile terminal guidance stage well.