虚拟现实技术中运动目标RCS及轨迹计算

【作者】 李民权；

【导师】 吴先良；

【作者基本信息】 安徽大学 ， 电磁场与微波技术， 2001， 硕士

【摘要】 本文对复杂目标进行几何建模，对静态、动态目标的电磁散射特性、多普勒频率及不同时刻目标的姿态进行了分析。 首先利用NURBS样条对任意复杂目标进行精确地构造，为其后的电磁计算打下基础。然后对静态复杂目标高频电磁散射特性进行研究。通过对典型算例进行图形电磁计算，证明了该方法具有较高的计算精度和效率，并且计算精度与目标的复杂程度无关。在此基础上，对动态复杂目标的电磁散射进行了研究。在分析运动目标的电磁散射时，首先引入两个不同的惯性坐标系—静止坐标系、运动坐标系。将静止坐标系下的入射场进行Lorentz变换，获得运动坐标系下的入射场，进而求出运动坐标系下的散射场，再进行Lorentz反变换，求出静止坐标系下的散射场。首次将可视化计算应用于复杂运动目标的RCS计算。经过必要的坐标调整，使目标表面上对散射场有贡献的部分以最大的显示比例处于可视区域。对可视区域象素求和，获得运动目标的雷达散射截面。同时对飞行目标几种特殊飞行状态的轨迹进行计算，给出不同时刻目标的姿态角。在引入合理的近似和简化的基础上，针对运动目标的多普勒频移进行研究，并给出多普勒信号的计算结果。更多还原

【Abstract】 In this paper ,complex targets are modeled in geometty. Not only scattering character and Doppler frequency but also real time flight path are analyzed. Firstly arbitrarily shaped targets are modeled in geometry by NURBS curves, then the EM scattering characters of radar targets in stationary reference frame are presented .The results of several typical scattering objects demonstrate that the visual method is advantageous in both accuracy and efficiency and the calculation accuracy is independent of complexity of the targets. While moving targets being analyzed, through Lorentz transfer, incident field in stationary reference frame is changed into locomotive reference frame ,then scattering field in locomotive reference frame can be gotten .Secondly ,through Lorentz inverse transfer scattering field in locomotive reference frame is changed into the scattering field in stationary reference frame. The visual graphical electromagnetic computation is applied to moving targets RCS calculation. Rool angle, Pitch angle, Yaw angle and position of moving targets are calculated .Through transferring coordinates and summing pixels of screen ,RCS of moving targets are gotten. Doppler field and frequency of moving targets are received.更多还原