An experimental concept for measuring sound-sound scattering of finite aperture acoustic beams in a water tank facility is presented. In order to achieve a measurable effect, the beams are collimated within their intersection domain by a focusing acoustic lens. A paraxial quasi-linear split step simulation tool has been developed and used in order to determine and optimize experiment setup parameters. The scattered part of the difference frequency field was measured and found to be compatible with simulations. Furthermore, the primary beams were also monitored in order to guarantee full compatibility with simulated propagation and compare the measured difference field with the overlap contribution. A spatially coherent post processing filtering was applied in order to improve the signal to noise ratio. A distinct clear scattering peak in the difference field has been identified propagating with the predicted off axis tilt angle.

中文翻译：

---

透镜介导的有限孔径光束通过声音散射声音

提出了一种测量水箱设施中有限孔径声束声散射的实验概念。为了达到可测量的效果，光束通过聚焦声透镜在其相交域内准直。已经开发并使用了近轴准线性分裂步骤仿真工具，以便确定和优化实验设置参数。测量了差频场的分散部分，发现与模拟兼容。此外，还对主光束进行了监控，以确保与模拟传播完全兼容，并将测得的差分场与重叠部分进行比较。为了提高信噪比，应用了空间相干的后处理滤波。