基于齐次坐标的微动建模与微多普勒特征分析

Micro-Motion Modeling and Micro-Doppler Analysis Based on Homogeneous Coordinates

针对目标微动数学模型表达不统一的问题,引入计算机图形学中的齐次坐标表示方法,给出了三维坐标系和旋转变换的齐次变换矩阵描述,推导了自旋、锥旋、进动和章动目标微动模型的通用矩阵表达。并分析了目标回波频移的组成,得到了微多普勒的理论表达式。微动回波Ga2bor变换时频图与微多普勒理论值的仿真结果表明,通用的矩阵表达可以简明且准确地描述目标的微动。

To solve the ununiformity of the micro-motion model, homogeneous coordinates often seen in computer graphics is used. Three-dimensional coordinates system and rotating transformation are described by homogeneous transformation matrix. The uniform micro-motion models of spinning, coning, precession and nutation target are given based on homogeneous transformation matrix. The frequency shift of the echo is analyzed then, and the mathematical formula of micro-Doppler is derived. Then the mathematical micro-Doppler is calculated and the time-frequency image of the micro-motion echo is got by Gabor transformation. The simulation results confirmed that the model is valid.