Application of Ultra-Low Cost Differential Pressure Sensors to the Large N Acoustic Sensor Problem

TDA Research, Inc. (TDA), designed, built, and tested a dense array of 100 very low cost infrasonic sensors. Due to their low cost (1/100x-1/10x the cost of other infrasound sensors), they can be economically deployed in very large numbers; such large arrays can gather more information than a few expensive sensors. They are sensitive from 0.1 Hz - 100 Hz down to 0.08 Pa. We tested the sensors in small sub-arrays (N=4 to N=12) with higher frequency signals (30 Hz - 100 Hz) and in a full array of 100 sensors with low frequency signals using a rotary subwoofer (2 Hz - 20 Hz) and a propane cannon at DTRA’s facility at the Kirtland Airforce Base. The sensors performed extremely well, recording all of the signals and in fact performed as well as reference sensors costing roughly 40 times more. A dense array of infrasound sensors will have significant advantages to a sparse array. For instance, data can be collected on a more granular level, providing information on how infrasound propagates through space over time within small distances and short time frames. In a practical sense, such arrays can do a better job of locating and tracking explosions or tornadoes.