HumSensE32: A low-cost infrasound sensor node for volcano monitoring

Infrasound is the acoustic fingerprint of a volcano and carries vital information that reveals its activities characteristics. In conjunction with seismic monitoring, it can help in studying the characteristics of volcanic activities, potentially reducing casualties and saving lives. The International Monitoring System (IMS) infrasound network, the only global infrasound network of its kind, indirectly plays an essential role in volcano monitoring and is relatively scattered in the Southeast Asia region, which is not ideal for infrasound volcano study in this region. This paper presents an open source, low-cost, telemetry-capable infrasound sensor node, HumSensE32, which enables mass sensor nodes deployment for localized infrasound monitoring and study. It features data logging and data forwarding capability using either wireless or wired communication (cellular/Wi-Fi/Ethernet), enabling both local storage and remote access for real-time monitoring. Its low-power consumption enables long-term deployment with minimal maintenance required, making it well-suited for extended field monitoring missions. Its small footprint allows easy handling and quick installation with minimal effort. It can be easily programmed with PlatformIO for custom operations, whichever suits the monitoring mission. To validate HumSensE32, field deployment has been conducted alongside scientific grade infrasound sensor, Seismo Wave MB3 series infrasound sensor, as reference. HumSensE32 has demonstrated strong linear correlation with reference sensor across 0.1 Hz to 10 Hz frequency band with Pearson correlation coefficient r above 0.95 and spectral coherence Cxy above 0.95 when tested under similar environmental conditions. This repository includes hardware, software and design files required to build and run HumSensE32 infrasound sensor.