激光反射层析成像仿真方法研究

Simulation Method of Laser Reflection Tomography Imaging

为了解决复杂结构和形状的目标进行消隐数值计算时计算量大,精度较低的难点,提出基于OpenGL的目标消隐及可见部分显示方法,启用深度缓冲区进行深度测试,利用计算机图形加速卡在硬件层级迅速实现目标消隐并得到面元距离信息,提高了计算效率和精度,并通过一次光照获取目标面元与探测视线夹角的余弦值。考虑激光脉冲的时空分布特点,结合仿真得到的目标反射率分布,采用卷积模型计算目标的激光回波波形,仿真分析了发射激光脉宽、目标表面材料对目标激光反射层析成像质量的影响。

This study proposes a method of object shading and display of the object's visible parts based on OpenGL, which is used to solve the problems of large calculation amount and low accuracy when the blanking process of a complex structure object is realized by a numerical method. By enabling depth buffers and depth testing, the computer graphics acceleration card is used in a hardware level to quickly achieve the goal of hidden and surface element distance information. The calculation efficiency and accuracy are improved. Moreover, the cosine of the angle between the target element and the detection line of sight is obtained by a single illumination. Subsequently, the target reflectivity distribution is obtained by a simulation considering the temporal and spatial distribution characteristics of the laser pulse. The convolution model is then used to calculate the laser echo waveform of the target. The effects of the laser pulse width and the target surface material on the quality of laser reflection tomography are analyzed using the presented method.