Natural and anthropogenic infrasound may travel vast distances, making it an invaluable resource for monitoring phenomena such as nuclear explosions, volcanic eruptions, severe storms, and many others. Typically, these waves are captured using pressure sensors, which cannot encode the direction of arrival—critical information when the source location is not known beforehand. Obtaining this information therefore requires arrays of sensors with apertures ranging from tens of meters to kilometers depending on the wavelengths of interest. This is often impractical in locations that lack the necessary real estate (urban areas, rugged regions, or remote islands); in any case, it requires multiple power, digitizer, and telemetry deployments. Here, the theoretical basis behind a compact infrasound direction of arrival sensor based on the acoustic metamaterials is presented. This sensor occupies a footprint that is orders of magnitude smaller than the span of a typical infrasound array. The diminutive size of the unit greatly expands the locations where it can be deployed. The sensor design is described, its ability to determine the direction of arrival is evaluated, and further avenues of study are suggested.

中文翻译：

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使用声学超材料的定向次声传感

自然和人为次声可能传播很远的距离，使其成为监测核爆炸、火山爆发、严重风暴等许多现象的宝贵资源。通常，这些波是使用压力传感器捕获的，当源位置事先未知时，压力传感器无法对到达方向进行编码 - 关键信息。因此，获取这些信息需要传感器阵列，其孔径根据感兴趣的波长从几十米到几公里不等。在缺乏必要房地产的地方（城市地区、崎岖地区或偏远岛屿），这通常是不切实际的；无论如何，它需要多个电源、数字化仪和遥测部署。这里，介绍了基于声学超材料的紧凑型次声波到达方向传感器背后的理论基础。该传感器占用的占地面积比典型次声阵列的跨度小几个数量级。该装置的小型化极大地扩展了其部署地点。描述了传感器设计，评估了其确定到达方向的能力，并建议了进一步的研究途径。