A "DIY" data acquisition system for acoustic field measurements under harsh conditions

TL;DR

This paper introduces a low-cost, portable acoustic data acquisition system based on Raspberry Pi for field measurements in harsh environments, demonstrated on active volcanoes to analyze eruption sounds.

Contribution

It presents a modular, high-frequency acoustic recording system with GPS synchronization, enabling effective deployment as a microphone array in challenging conditions.

Findings

Successfully deployed 20 modules on Stromboli volcano

Captured high-resolution acoustic data of eruptions

Identified sound source positions during volcanic activity

Abstract

Monitoring active volcanos is an ongoing and important task helping to understand and predict volcanic eruptions. In recent years, analysing the acoustic properties of eruptions became more relevant. We present an inexpensive, lightweight, portable, easy to use and modular acoustic data acquisition system for field measurements that can record data with up to 100~kHz. The system is based on a Raspberry Pi 3 B running a custom build bare metal operating system. It connects to an external analog - digital converter with the microphone sensor. A GPS receiver allows the logging of the position and in addition the recording of a very accurate time signal synchronously to the acoustic data. With that, it is possible for multiple modules to effectively work as a single microphone array. The whole system can be build with low cost and demands only minimal technical infrastructure. We demonstrate a possible use of such a microphone array by deploying 20 modules on the active volcano \textit{Stromboli} in the Aeolian Islands by Sicily, Italy. We use the collected acoustic data to indentify the sound source position for all recorded eruptions.