水下目标回波特性计算的图形声学方法

Graphical acoustics computing method for echo characteristics calculation of underwater targets

根据Kirchhoff近似公式建立了一种水下目标回波特性实时工程预报的新方法-可视化图形声学计算方法GRACO (Graphical Acoustics Computing)。该方法利用三维图形处理系统,采用建模软件对水下复杂目标进行几何建模,并基于OpenGL技术把几何模型转化为屏幕上目标的可视化像素图形,获取像素中包含的目标表面法向量和空间距离信息,最后通过把回波特性预报中的面积分转化为屏幕上可视化图形的像素求和计算,完成水下目标回波特性预报。计算结果表明图形声学方法有较高的精度,计算速度比板块元方法快9-10倍。

On the basis of Kirchhoff approximate equation, a new approach - GRACO （Graphical Acoustics Computing） is developed for forecasting the echo characteristics of underwater targets in real time, Using 3D graphic processing system, the geometrical model of complex underwater target is established. Basing on OpenGL, the geometrical model is transformed into the visual image on the computer＇s screen, and target surface＇s normal vector and space included in the information of pixels are obtained. Instead of computing the surface integral directly, the forecast of echo characteristic of underwater target is achieved by calculating the sum of the contribution from all the pixels in the screen image. Numerical results show that GRACO method enjoys high precision and computing speed is 9 to 10 times faster than the Planar Elements Method.